Hazard Plain Automated baseline

Norfolk County, MA

Risk-assessment baseline packet

County FIPS:
25021
Release:
2026-10
Data as of:
2026-09-30
Storm Events data through:
2026-06-30

Hazard Plain is an independent product built from public federal data. It is not a FEMA document and is not reviewed or endorsed by FEMA or any state agency.

Hazard Plain release 2026-10, as of 2026-09-30.

Summary

Plan status as of 2026-09-30: No county-level plan row in FEMA data.

Highest expected annual loss (FEMA National Risk Index, modeled total; see B1-a): Inland Flooding ($103,067,766 a year), Hurricane ($15,628,146) and Earthquake ($8,881,734).

The tables that follow are organized by the items of FEMA's Local Mitigation Plan Review Tool, Element B (B1-a to B2-c); each heading says which item its tables support.

Plan clock

No county-level plan row in FEMA data

What changed since your last plan

Not available. No county-level plan row in FEMA data, so there is no approval date to count from.

Sources: 1, 2, 4, 6 (numbered list at the end)

Plan status for every jurisdiction listed in this county: 29 rows, in the section "Plan clock: Plan status for every jurisdiction listed in this county" on the following pages.

State plan status and tribal plans in this state: see the state page.

Plan clock

Plan status for every jurisdiction listed in this county

Source: 1

JurisdictionTypeStatusPlanApprovedExpiresDays to expirynegative = days since expiryUpdate underway
Braintree Town cityCityApproved, expires 2029-11-19Town of Braintree, MA Hazard Mitigation Plan Update April 2024 (FEMA plan 109891)2024-11-202029-11-191,146
Franklin Town cityTownExpired on 2026-01-21Town of Franklin Hazard Mitigation Plan 2020 Update (FEMA plan 106880)2021-01-222026-01-21-252
Quincy cityCityApproved, expires 2030-12-04City of Quincy Multi-Hazard Mitigation Plan (FEMA plan 110472)2025-12-052030-12-041,526
Randolph Town cityTownExpired on 2021-09-20Town of Randolph Hazard Mitigation Plan 2014 Update (FEMA plan 12264)2016-09-202021-09-20-1,836
Weymouth Town cityTownApproved, expires 2026-11-28Town of Weymouth Hazard Mitigation Plan 2021 Update (FEMA plan 107812)2021-11-292026-11-2859
Avon townTownApproved, expires 2027-01-10Town of Avon Massachusetts Hazard Mitigation Plan and Municipal Vulnerability Report (FEMA plan 107770)2022-01-112027-01-10102
Bellingham townTownExpired on 2025-11-03Town of Bellingham Hazard Mitigation Plan 2020 Update (FEMA plan 106813)2020-11-042025-11-03-331
Brookline townTownApproved, expires 2028-11-27Town of Brookline, MA Hazard Mitigation Plan Update June 2023 (FEMA plan 109173)2023-11-282028-11-27789
Canton townTownExpired on 2023-06-21Town of Canton Hazard Mitigation Plan 2017 Update (Draft) (FEMA plan 104767)2018-06-222023-06-21-1,197
Cohasset townTownExpired on 2025-11-11Town of Cohasset Hazard Mitigation Plan 2020 Update (FEMA plan 106725)2020-11-122025-11-11-323
Dedham townTownExpired on 2026-02-232020 Hazard Mitigation Plan Update Town of Dedham, Massachusetts (FEMA plan 106745)2021-02-242026-02-23-219
Dover townTownApproved, expires 2027-09-25Town of Dover Draft Hazard Mitigation Plan 2022 Update (FEMA plan 108146)2022-09-262027-09-25360
Foxborough townTownExpired on 2025-10-14Town of Foxborough Hazard Mitigation Plan (FEMA plan 106686)2020-10-152025-10-14-351
Holbrook townTownNo approved plan on recordnonenonenoneFEMA tracker shows a plan in review
Medfield townTownExpired on 2024-09-19Town of Medfield Hazard Mitigation Plan 2019 Update (FEMA plan 105925)2019-09-202024-09-19-741
Medway townTownApproved, expires 2030-01-12Town of Medway Hazard Mitigation Plan 2024 Update (FEMA plan 109747)2025-01-132030-01-121,200
Millis townTownApproved, expires 2030-11-12Town of Millis Hazard Mitigation Plan 2025 Update (FEMA plan 110882)2025-11-132030-11-121,504
Milton townTownApproved, expires 2027-01-06Town of Milton Hazard Mitigation Plan 2021 Update (FEMA plan 107811)2022-01-072027-01-0698
Needham townTownExpired on 2026-01-21Town of Needham Hazard Mitigation Plan 2020 Update (FEMA plan 106729)2021-01-222026-01-21-252
Norfolk townTownApproved, expires 2029-02-27Town of Norfolk Hazard Mitigation Plan 2023 Update (FEMA plan 109227)2024-02-282029-02-27881
Norwood townTownApproved, expires 2030-09-15Town of Norwood Hazard Mitigation Plan 2024 Update (FEMA plan 110315)2025-09-162030-09-151,446
Plainville townTownExpired on 2013-04-02Southeastern Regional Planning and Economic Development District (SRPEDD) (FEMA plan 12041)2008-04-032013-04-02-4,929
Sharon townTownApproved, expires 2030-10-19Town of Sharon Hazard Mitigation Plan 2024 Update (FEMA plan 110410)2025-10-202030-10-191,480
Stoughton townTownApproved, expires 2030-02-11Towns of Abington, Easton, and Stoughton Natural Hazard Mitigation Plan 2023 Update (FEMA plan 109886)2025-02-122030-02-111,230
Walpole townTownExpired on 2022-05-31Town of Walpole Hazard Mitigation Plan Draft 2017 Plan Update (FEMA plan 104203)2017-06-012022-05-31-1,583
Wellesley townTownApproved, expires 2029-02-22Town of Wellesley, MA Hazard Mitigation Plan (FEMA plan 109310)2024-02-232029-02-22876
Westwood townTownApproved, expires 2029-04-11Westwood, MA Hazard Mitigation Plan 2022 Update February 2023 (FEMA plan 108925)2024-04-122029-04-11924
Wrentham townTownExpired on 2023-11-26Town of Wrentham Hazard Mitigation Plan 2018 Update (FEMA plan 105354)2018-11-272023-11-26-1,039
Name not given in FEMA data (ID NM01_12386)College/UniversityExpired on 2021-05-12University of Massachusetts Multi-Campus Hazard Mitigation Plan (FEMA plan 12383)2016-05-122021-05-12-1,967

Supports FEMA checklist item B1-a: hazard identification

Hazards NRI does not cover (local data needed)

  • dam failure (incl. upstream dams)
  • levee failure
  • flash flood as its own subtype
  • ice jams
  • debris flows
  • erosion (riverine and coastal)
  • land subsidence and sinkholes
  • expansive soils

The 18 National Risk Index hazards, ranked by expected annual loss (EAL)

Sources: 5, 6

Rank by EALHazardNRI risk ratingEAL ratingEAL buildingsmodeled dollars per yearEAL agriculturemodeled dollars per yearCost of expected deaths and injuriesFEMA's dollar value per year, not property damageEAL total (see note)modeled dollars per yearStorm Events records, 1996 to 2026-06-30countStorm Events coverage note
1Inland FloodingRelatively HighRelatively High$102,429,843$24$637,899$103,067,766148
2HurricaneRelatively ModerateRelatively High$15,130,182$51,197$446,768$15,628,1466
3EarthquakeRelatively ModerateRelatively Moderate$7,106,937n/a$1,774,797$8,881,734Storm Events does not record earthquakes.
4Coastal FloodingRelatively HighRelatively High$5,070,024n/a$20,621$5,090,64571
5Heat WaveRelatively ModerateRelatively Moderate$5$914$3,861,543$3,862,46230
6Cold WaveRelatively ModerateRelatively Moderate$2,308$689$3,321,296$3,324,2939
7TornadoRelatively ModerateRelatively Moderate$2,798,739$65$389,797$3,188,6018
8LightningRelatively HighRelatively High$202,168n/a$1,049,609$1,251,77756
9Ice StormRelatively HighRelatively High$1,155,664n/a$35,116$1,190,7800No recorded events in Storm Events since 1996 (data through 2026-06-30).
10Strong WindRelatively ModerateRelatively Moderate$650,411under $1$488,760$1,139,170606Includes 189 High Wind and 190 Strong Wind records (NOAA non-thunderstorm wind types, outside NRI's Strong Wind definition).
11DroughtRelatively LowRelatively Lown/a$97,921n/a$97,92113
12Winter WeatherRelatively LowRelatively Moderate$56,415$3$24,851$81,269166
13WildfireVery LowVery Low$55,475$1$5,391$60,8671
14HailVery LowVery Low$32,194$44$10,374$42,61375
15LandslideRelatively LowRelatively Low$8,740n/a$636$9,3760No recorded events in Storm Events since 1996 (data through 2026-06-30).
TsunamiInsufficient DataInsufficient Datan/an/an/an/a0No recorded events in Storm Events since 1996 (data through 2026-06-30).

Total = buildings + agriculture + population equivalence; FEMA values each expected death (or 10 injuries) at $13.7 million (2024 dollars).

NRI risk rating combines expected annual loss with social vulnerability and community resilience; EAL rating rates expected annual loss alone. Both compare this county with all U.S. counties.

Local data needed: state and local landslide and tsunami records (Storm Events records these hazards only in part).

Not applicable to this county per NRI, with no federal declaration and no Storm Events record since 1996: avalanche and volcanic activity. That is the evidence for leaving them out of the plan.

The state hazard mitigation plan also lists hazards for this county; FEMA asks the plan to explain any hazard it leaves out.

Supports FEMA checklist item B1-b: hazard location

Affects the whole county (national data give no location within it): Cold Wave, Drought, Hail, Heat Wave, Ice Storm, Lightning, Strong Wind and Winter Weather.

Coastal Flooding and Inland Flooding: The FEMA Flood Insurance Rate Map (FIRM) is the required location source for flooding. See the FEMA Flood Map Service Center (https://msc.fema.gov) for this county.

Hazards that vary within the county: highest-rated census tracts

Source: 5

HazardHighest-rated census tractsNRI risk rating, score 0 to 100
Earthquaketract 4191 (Relatively Moderate, 80.6); tract 4035.01 (Relatively Moderate, 79.8); tract 4041 (Relatively Moderate, 79.0)
Hurricanetract 4191 (Relatively Moderate, 83.6); tract 4035.01 (Relatively Moderate, 82.9); tract 4571 (Relatively Moderate, 82.8)
Landslidetract 4051 (Relatively Low, 92.3); tract 4231.02 (Relatively Low, 88.4); tract 4412.03 (Relatively Low, 87.7)
Tornadotract 4035.01 (Relatively Low, 46.7); tract 4034 (Relatively Low, 43.8); tract 4051 (Relatively Low, 42.4)
Tsunamino tract has a National Risk Index rating for this hazard
Wildfiretract 4051 (Relatively Low, 82.7); tract 4034 (Relatively Low, 74.3); tract 4061.02 (Relatively Low, 72.6)

Up to 3 census tracts per hazard, highest National Risk Index rating first, then highest score; a tract number is the Census tract number (for example 4191 is Census Tract 4191). FEMA's Resilience Analysis and Planning Tool maps the National Risk Index for every tract: https://www.fema.gov/emergency-managers/practitioners/resilience-analysis-and-planning-tool

Supports FEMA checklist item B1-c: hazard extent

Extent: scale, observed range and worst recorded event per hazard

Sources: 6, 7

HazardScaleRecordscount and yearsObserved rangeWorst recorded eventMost damaging (when different)How it applies to jurisdictionsNote
Coastal Flood, Storm Surge/Tidenone in data (flood depth: FIRM)71 records, 1996 to 2024 (70 zone-level)Coastal Flood, 2013-02-09, $9,200,000 property; $0 crops (2013 dollars); NWS zone MAZ019Event records naming jurisdictions in the plan: Quincy city (1 record). Zone-level records (70) apply countywide.Flood depth: see the FEMA Flood Insurance Rate Map.
Cold/Wind Chill, Extreme Cold/Wind Chillwind chill9 records, 1999 to 2018 (9 zone-level)1 day to 2 days (median 1 day); 6 with a recorded value2 consecutive days, 2007-02-03 to 2007-02-04, 1 direct death, zone-levelCountywide (zone-level records).Cold/Wind Chill records from May to September (a frost night, not a cold wave) are counted but not used for the longest run.
Frost/Freeze (outside NRI's Cold Wave definition)crop damage0
DroughtU.S. Drought Monitor scale (D0 to D4)13 records, 1999 to 2017 (13 zone-level)1 day to 183 days (median 17.5 days); 4 with a recorded value183 days (about 6.0 months), 2016-07-26 to 2017-01-24, a run of 9 consecutive Storm Events drought records, zone-levelCountywide (zone-level records).Storm Events enters a drought at D2 or worse east of the Rockies and D3 or worse from the Rockies west (NWS Instruction 10-1605); NRI drought counts D3 and D4 only.
EarthquakeModified Mercalli (local data)0Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hailhail size (inches)82 records, 1965 to 20240.75 in to 2 in (median 0.88 in); 82 with a recorded value2 in hail, 2020-06-28; same size also recorded on 1969-04-19Event records naming jurisdictions in the plan: Foxborough town (5 records), Needham town (5 records), Bellingham town (4 records), Stoughton town (4 records), Walpole town (4 records), Wrentham town (4 records), Avon town (3 records), Medway town (3 records), Norfolk town (3 records), Quincy city (3 records); and 9 more jurisdictions (see the Excel file).
Excessive Heat, Heatheat index (in event narratives)30 records, 1996 to 2018 (30 zone-level)1 day to 3 days (median 1 day); 14 with a recorded value3 consecutive days, 1999-09-07 to 1999-09-09, zone-levelCountywide (zone-level records).Heat records from November to March (unseasonable warmth, not a heat wave) are counted but not used for the longest run.
Hurricane, Tropical Storm, Tropical DepressionSaffir-Simpson6 records, 2011 to 2021 (6 zone-level)Strongest recorded: Tropical Storm record, 2011-08-28, $3,500,000 property; $0 crops (2011 dollars); NWS zone MAZ013Countywide (zone-level records).Storm Events files every zone of a storm's episode under the storm's type; flooding from the storm is filed as Flood or Flash Flood records.
Ice StormSperry-Piltz ice scale (local data)0
Flash Flood, Flood, Lakeshore Flooddamage and flood days (flood depth: FIRM)148 records, 1996 to 2025 (11 zone-level)Flash Flood, 2020-06-28, $30,000,000 property; $0 crops (2020 dollars)Event records naming jurisdictions in the plan: Walpole town (8 records), Quincy city (6 records), Brookline town (5 records), Holbrook town (4 records), Needham town (4 records), Norwood town (4 records), Dover town (3 records), Sharon town (3 records), Wellesley town (3 records), Wrentham town (3 records); and 10 more jurisdictions (see the Excel file). Zone-level records (11) apply countywide.Flood depth: see the FEMA Flood Insurance Rate Map. Storm Events damage is often $0 or blank for floods, major ones included; FEMA Public Assistance by declaration (B1-d) shows which floods cost the most.
Debris Flownone (count and damage only)0
Lightningannualized frequency (the measure FEMA's Local Mitigation Planning Handbook names)56 records, 1996 to 2023Lightning, 2009-05-24, $1,000,000 property; $0 crops (2009 dollars)Event records naming jurisdictions in the plan: Milton town (5 records), Sharon town (4 records), Stoughton town (3 records), Wrentham town (3 records), Needham town (2 records), Norfolk town (2 records), Norwood town (2 records), Plainville town (2 records), Quincy city (2 records), Bellingham town (1 record); and 7 more jurisdictions (see the Excel file).Storm Events lists lightning with damage or casualties.
High Wind and Strong Wind (outside NRI's Strong Wind definition)wind speed (kt and mph)379 records, 1996 to 2025 (379 zone-level)27 kt (31 mph) to 85 kt (98 mph) (median 50 kt (58 mph)); 314 with a recorded value85 kt (98 mph) measured gust, High Wind, 2006-01-18; NWS zone MAZ016High Wind, 2012-10-29, $3,000,000 property; $0 crops (zone total, 2012 dollars)Countywide (zone-level records).
Thunderstorm Windwind speed (kt and mph)254 records, 1956 to 202640 kt (46 mph) to 70 kt (81 mph) (median 50 kt (58 mph)); 236 with a recorded value70 kt (81 mph), measurement type not recorded, Thunderstorm Wind, 1999-07-06Thunderstorm Wind, 2016-07-22, $50,000 property; $0 crops (2016 dollars)Event records naming jurisdictions in the plan: Walpole town (14 records), Brookline town (13 records), Medway town (13 records), Milton town (11 records), Wellesley town (11 records), Needham town (9 records), Quincy city (9 records), Foxborough town (8 records), Wrentham town (8 records), Medfield town (6 records); and 13 more jurisdictions (see the Excel file).
TornadoEnhanced Fujita (Fujita before Feb 2007)15 records, 1953 to 2023F/EF0 to F/EF3 (median F/EF0); 15 with a recorded valueF3 tornado, 1953-06-09, 13.1 mi path length (whole path, pre-1996), 667 yd wide, $2,500,000 property; crops not recorded (1953 dollars), 15 direct injuriesEvent records naming jurisdictions in the plan: Stoughton town (2 records), Bellingham town (1 record), Millis town (1 record), Wrentham town (1 record).Before 1996 a tornado is listed once, under the county where it began, with its whole path's rating and length; from 1996 on, each county lists its own segment. Length is not used to rank tornadoes (see Methods).
Tsunaminone (count and damage only)0
Wildfireacres burned (local data)1 record, 2012 (1 zone-level)No damage reported in 1 record.Countywide (zone-level records).
Winter Storm, Heavy Snow, Blizzard, Lake-Effect Snow, Winter Weather, Sleetnone in data (snowfall: local data)166 records, 1996 to 2026 (166 zone-level)Heavy Snow, 1996-01-07, $7,000,000 property; crops not reported (1996 dollars); NWS zone MAZ015Countywide (zone-level records).

Where a hazard names more than 10 jurisdictions, the table lists the 10 with the most records; every one is in the Excel file, sheet "B1-c Extent".

In event narratives only (local data needed): wind chill, temperature, heat index, ice thickness, acres burned and snow depth; any physical measure of debris flow, lightning and tsunami.

Storm Events records are more complete after 1996; before 1996 only Tornado (from 1950), Hail and Thunderstorm Wind (from 1955) exist. Zone-level records from zones that no NWS zone-county file places in this county (mostly before 2020) are not counted here (the Methods page explains the zone matching).

Dollars are nominal (as reported), labeled with the year; not adjusted for inflation.

Supports FEMA checklist item B1-d: previous occurrences

Federal declarations for this county: 38 declarations covering 29 separate hazard incidents counted in this packet (declarations for the same incident count once; non-natural and evacuation-only declarations are not counted).

No county-level plan row in FEMA data, so there is no approval date to count from.

Federal disaster declarations for this county

Sources: 1, 2, 3

DeclaredIncident beganFEMA numberTypeTitleMapped hazardCounty Public Assistancefederal share obligated, nominal dollarsFlagsNotes
2023-09-152023-09-15EM-3599-MAEmergencyHurricane LeeHurricaneno Public Assistance recordedwithin last 5 years
2022-04-182022-01-28DR-4651-MAMajor disasterSevere Winter Storm and SnowstormWinter Weather$5,279,440.40within last 5 years
2020-03-272020-01-20DR-4496-MAMajor disasterCOVID-19 PandemicNon-natural, not counted$51,481,681.05
2020-03-132020-01-20EM-3438-MAEmergencyCOVID-19Non-natural, not countedno Public Assistance recordedsame incident as DR-4496
2018-07-192018-03-13DR-4379-MAMajor disasterSevere Winter Storm and SnowstormWinter Weather$4,047,879.40
2018-06-252018-03-02DR-4372-MAMajor disasterSevere Winter Storm and FloodingInland Flooding; Winter Weather$6,875,355.88
2015-04-132015-01-26DR-4214-MAMajor disasterSevere Winter Storm, Snowstorm, and FloodingInland Flooding; Winter Weather$9,261,345.75
2013-04-192013-02-08DR-4110-MAMajor disasterSevere Winter Storm, Snowstorm, and FloodingInland Flooding; Winter Weather$4,855,562.13
2013-04-172013-04-15EM-3362-MAEmergencyExplosionsNon-natural, not counted$39,796.74
2012-10-282012-10-27EM-3350-MAEmergencyHurricane SandyHurricaneno Public Assistance recorded
2011-11-012011-10-29EM-3343-MAEmergencySevere StormHazard not mapped (severe storm title names no single hazard); not countedno Public Assistance recorded
2011-09-032011-08-27DR-4028-MAMajor disasterTropical Storm IreneHurricane$2,024,728.03
2011-08-262011-08-26EM-3330-MAEmergencyHurricane IreneHurricaneno Public Assistance recordedsame incident as DR-4028
2011-03-072011-01-11DR-1959-MAMajor disasterSevere Winter Storm and SnowstormWinter Weather$3,091,794.98
2010-09-022010-09-01EM-3315-MAEmergencyHurricane EarlHurricane$42,493.87
2010-05-032010-05-01EM-3312-MAEmergencyWater Main BreakNon-natural, not countedno Public Assistance recorded
2010-03-292010-03-12DR-1895-MAMajor disasterSevere Storms and FloodingInland Flooding$3,400,456.04
2005-11-102005-10-07DR-1614-MAMajor disasterSevere Storms and FloodingInland FloodingPA not declared for this county
2005-09-132005-08-29EM-3252-MAEmergencyHurricane Katrina EvacuationHurricane: evacuation support, not a local hazard event; not countedno Public Assistance recorded
2005-02-172005-01-22EM-3201-MAEmergencyRecord and/or Near Record SnowWinter Weather$4,036,317.79
2004-04-212004-04-01DR-1512-MAMajor disasterFloodingInland FloodingPA not declared for this county
2004-01-152003-12-06EM-3191-MAEmergencySnowWinter Weather$3,019,806.95
2003-03-112003-02-17EM-3175-MAEmergencySnowWinter Weather$2,146,207.81
2001-04-102001-03-05DR-1364-MAMajor disasterSevere Storms and FloodingInland FloodingPA not declared for this county
2001-03-282001-03-05EM-3165-MAEmergencySnowWinter Weather$2,254,284.92
1998-06-231998-06-13DR-1224-MAMajor disasterHeavy Rains and FloodingInland FloodingPA not declared for this county
1996-10-251996-10-20DR-1142-MAMajor disasterExtreme Weather Conditons and FloodingInland Floodingno Public Assistance recorded
1996-10-231996-10-20EM-3119-MAEmergencyExtreme Weather Conditions and FloodingInland Floodingno Public Assistance recordedsame incident as DR-1142
1996-01-241996-01-07DR-1090-MAMajor disasterBlizzard of 96Winter Weatherno Public Assistance recorded
1993-03-161993-03-13EM-3103-MAEmergencyBlizzards, High Winds & Record SnowfallWinter Weatherno Public Assistance recorded
1992-12-211992-12-11DR-975-MAMajor disasterWinter Coastal StormCoastal Floodingno Public Assistance recorded
1991-11-041991-10-30DR-920-MAMajor disasterCoastal StormCoastal Floodingno Public Assistance recorded
1991-08-261991-08-19DR-914-MAMajor disasterHurricane BobHurricaneno Public Assistance recorded
1987-04-181987-03-30DR-790-MAMajor disasterSevere Storms & FloodingInland FloodingPA not declared for this county
1985-10-281985-09-27DR-751-MAMajor disasterHurricane GloriaHurricaneno Public Assistance recorded
1978-02-101978-02-06DR-546-MAMajor disasterCoastal Storms, Flood, Ice & SnowCoastal Floodingno Public Assistance recorded
1972-09-281972-09-28DR-357-MAMajor disasterToxic Algae in Coastal WatersFishing Losses: economic loss, not a physical hazard event; non-natural, not countedPA not declared for this county
1972-03-061972-03-06DR-325-MAMajor disasterSevere Storms & FloodingInland Floodingno Public Assistance recorded

County Public Assistance: applicants the FEMA record places in this county, including any state agencies FEMA files there; statewide rows are listed on the state page; federal share obligated, nominal dollars.

Statewide declarations

Source: 2

DeclaredIncident beganFEMA numberTypeTitleMapped hazard
1955-08-201955-08-20DR-43-MAMajor disasterHurricane & FloodsHurricane (primary); also designated: Inland Flooding
1954-09-021954-09-02DR-22-MAMajor disasterHurricanesHurricane (primary); also designated: Inland Flooding
1953-06-111953-06-11DR-7-MAMajor disasterTornadoTornado

FEMA recorded these with designated area Statewide and no county, so they are listed on every county page in the state and not counted with county rows. Local data needed: whether each one affected this county.

1 Fire Management declaration (1995-09-12 to 1995-09-12) FEMA filed as Statewide with no county; each names one local fire. Listed on the state page.

Previous occurrences by hazard, with explicit no-event rows

Sources: 2, 6, 7

HazardStorm Events records, all years on file(years in the Period column)Since plan approvalrecordsIn the 12 months before plan approvalrecordsLast 5 yearsrecordsDeclared incidents, all yearsseparate disastersDeclared since approvalseparate disastersPeriodStatement
Coastal Flooding71931996 to 2026-06-30
Cold Wave9001996 to 2026-06-30
Drought13001996 to 2026-06-30
Earthquake000Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hail82401955 to 2026-06-30
Heat Wave30001996 to 2026-06-30
Hurricane6061996 to 2026-06-30
Ice Storm0001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Inland Flooding14827111996 to 2026-06-30
Landslide0001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Lightning56301996 to 2026-06-30
Strong Wind6335501955 to 2026-06-30Includes 189 High Wind and 190 Strong Wind records.
Tornado15301950 to 2026-06-30
Tsunami0001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Wildfire1001996 to 2026-06-30
Winter Weather16610121996 to 2026-06-30

Notable Storm Events records

Sources: 1, 6, 7

DateEvent typeMagnitude or extentDamagenominal dollarsDeaths, injuriesdirect onlyLocationWhy listed
2020-06-28Flash Flood$30,000,000 property; $0 crops (2020 dollars)0, 0NORWOODB1-c worst recorded: Flash Flood, Flood, Lakeshore Flood
2016-02-05Heavy Snow$100,000 property; $0 crops (zone total, 2016 dollars)2, 0NWS zone MAZ013 (WESTERN NORFOLK), zone-leveldeaths or injuries recorded
2013-02-09Coastal Flood$9,200,000 property; $0 crops (zone total, 2013 dollars)0, 0NWS zone MAZ019 (EASTERN PLYMOUTH), zone-levelB1-c worst recorded: Coastal Flood, Storm Surge/Tide
2011-08-28Tropical Storm$3,500,000 property; $0 crops (zone total, 2011 dollars)0, 0NWS zone MAZ013 (WESTERN NORFOLK), zone-levelB1-c worst recorded: Hurricane, Tropical Storm, Tropical Depression
2009-05-24Lightning$1,000,000 property; $0 crops (2009 dollars)0, 0EAST WALPOLEB1-c worst recorded: Lightning
2007-02-03Extreme Cold/Wind Chill$0 property; $0 crops (zone total, 2007 dollars)1, 0NWS zone MAZ015 (SUFFOLK), zone-levelB1-c worst recorded: Cold/Wind Chill, Extreme Cold/Wind Chill
2006-01-18High Wind85 kt (98 mph) measured gust$20,000 property; crops not reported (zone total, 2006 dollars)0, 0NWS zone MAZ016 (EASTERN NORFOLK), zone-levelB1-c worst recorded: High Wind and Strong Wind
1999-09-07Heatdamage not reported0, 0NWS zone MAZ016 (EASTERN NORFOLK), zone-levelB1-c worst recorded: Excessive Heat, Heat
1999-07-06Thunderstorm Wind70 kt (81 mph), measurement type not recordeddamage not reported0, 0WEYMOUTHB1-c worst recorded: Thunderstorm Wind
1999-07-05Heatdamage not reported2, 0NWS zone MAZ015 (SUFFOLK / ALSO PART OF NORFOLK), zone-leveldeaths or injuries recorded
1972-08-09TornadoF1, 4.9 mi path length (whole path, pre-1996), 30 yd wide$25,000 property; crops not recorded (1972 dollars)1, 6location not recordeddeaths or injuries recorded
1953-06-09TornadoF3, 13.1 mi path length (whole path, pre-1996), 667 yd wide$2,500,000 property; crops not recorded (1953 dollars)0, 15location not recordedB1-c worst recorded: Tornado

The full list is in the Excel file, sheet "B1-d Storm Events history" (1,230 rows).

Location is the place NOAA recorded, as written in its data; it need not be a jurisdiction in this plan.

Local data needed: state-declared emergencies, from your state emergency management agency (federal data do not include them).

Tribal and special-area declarations in this state are listed on the state page.

Supports FEMA checklist item B1-e: probability of future events

Probability: FEMA annualized frequency and descriptor per hazard

Sources: 5, 6

HazardFEMA annualized frequency (modeled)unit per rowUnitIn plain termsDescriptorDescriptor basisNRI events or days in its record period (hail, wind and tornado are area-weighted, so can be fractional)NRI periodLocationNote
Coastal Flooding7.92events per year at a location (modeled)about 7.9 per year at a given location in the countyHighly likelyFEMA annualized frequency (modeled)not shownmodeledsee B1-fDescriptor from NRI: the rate at a location is 1 or more a year, so the county rate is at least that.
Cold Wave1.3event-days per yearabout 1.3 days per yearLikelyStorm Events event-days in 6 of 30 years, 1996 to 2025 (20%)22.82005-11-12 to 2024-11-12 (19 years)countywide
Drought5.77event-days per yearabout 5.77 days per yearLikelyStorm Events event-days in 4 of 30 years, 1996 to 2025 (13.3%)2382000 to 2025 (25.25 years; D3 and D4 only)countywide
Earthquake0.00166annual probability at a locationchance a given location in the county has at least minor-damage shaking in a year: 0.166%not shownmodeledsee B1-fNo descriptor (Storm Events does not record earthquakes).
Hail1.84events per yearabout 1.84 per yearHighly likelyFEMA annualized frequency (modeled)74.9 (modeled)1986 to 2023 (38 years)countywide
Heat Wave6.07event-days per yearabout 6.07 days per yearLikelyStorm Events event-days in 9 of 30 years, 1996 to 2025 (30%)93.62005-11-12 to 2024-11-12 (19 years)countywide
Hurricane0.178events per yearabout 1 in 6 yearsLikelyFEMA annualized frequency (modeled)541851 to 2024 (Atlantic)see B1-fNRI counts hurricane and tropical storm tracks passing within storm-force wind range; federal declarations are in B1-d.
Ice Storm1.78event-days per yearabout 1.78 days per yearStorm Events event-days in 0 of 30 years, 1996 to 2025 (0%)1151946-12-31 to 2014-02-12 (67 years)countywideNo Storm Events ice storm record, 1996 to 2025
Inland Flooding2.86event-days per yearabout 2.86 days per yearLikelyStorm Events event-days in 23 of 30 years, 1996 to 2025 (76.7%)801996 to 2023 (28 years)see B1-f
Landslide0.234events per year (modeled)about 1 in 4 yearsLikelyFEMA annualized frequency (modeled)not shownmodeledsee B1-f
Lightning21days per year with a strikeabout 21 days per yearHighly likelyFEMA annualized frequency (modeled)not shown1995 to 2023 (29 years; CONUS)countywide
Strong Wind0.917events per yearabout 0.92 per yearLikelyFEMA annualized frequency (modeled)351986 to 2023 (38 years)countywide
Tornado0.0818events per yearabout 1 in 12 yearsPossibleFEMA annualized frequency (modeled)not shown1950 to 2023 (EF2+); 1986 to 2023 (EF0-1)see B1-f
Tsunamiannual probability at the most exposed location (used in place of a county value)Storm Events records in 0 of 30 years, 1996 to 2025 (0%)not shownmodeledsee B1-fNo descriptor: no Storm Events record 1996 to 2025
Wildfire0.0000615annual probability at a locationchance a given location in the county burns in a year: 0.00615%PossibleStorm Events records in 1 of 30 years, 1996 to 2025 (3.33%)not shownmodeledsee B1-f
Winter Weather13event-days per yearabout 13 days per yearHighly likelyStorm Events event-days in 28 of 30 years, 1996 to 2025 (93.3%)2282005-11-12 to 2024-11-12 (19 years)countywide

FEMA annualized frequency (modeled) is the National Risk Index v1.20 (December 2025) estimate of how often a hazard affects this county in a year; it is not recorded events divided by years, and its unit differs by hazard (events, event-days, or days with a lightning strike per year). For earthquake, wildfire, coastal flooding and tsunami the value is the chance (or number of events) at a location in the county, not across the county, so no "1 in N years" is given and the descriptor comes from Storm Events where it has a record (none for earthquake). The Methods page gives each hazard's method, from FEMA's National Risk Index Technical Documentation v1.20.

Where NRI gives event-days, the descriptor comes from the share of years with a Storm Events record; NRI's source records more events, so the two differ.

Descriptor scale used in this packet (defined per unit)

Sources: 5, 6

UnitDescriptorDefinition
events per yearHighly likely1 or more per year
events per yearLikelyabout once in 1 to 10 years
events per yearPossibleabout once in 10 to 100 years
events per yearUnlikelyless than once in 100 years
annual probabilityLikely10% to under 100% chance in a given year
annual probabilityPossible1% to under 10% chance in a given year
annual probabilityUnlikelyunder 1% chance in a given year
event-days (share of years)Highly likelyevent-days recorded in 90% or more of years
event-days (share of years)Likelyevent-days recorded in 10% to under 90% of years
event-days (share of years)Possibleevent-days recorded in some years but under 10% of years
lightning strike-daysHighly likelycloud-to-ground strikes on 1 or more days per year

Intensity bands: historical frequency (Storm Events)

Source: 6

HazardBandYearsEventscounty-coded recordsYears in periodEvents per yearevents / years
Hail1.00-1.99 in1996 to 202525300.833
Hail2.00 in+1996 to 20251300.0333
Thunderstorm Wind (counted as NRI Strong Wind)50-64 kt1996 to 2025203306.77
Thunderstorm Wind (counted as NRI Strong Wind)65 kt+1996 to 20252300.0667
Thunderstorm Wind (counted as NRI Strong Wind)unmeasured or below 50 kt1996 to 202519300.633
TornadoEF0-11996 to 20258300.267
TornadoEF2-31996 to 20250300
TornadoEF4-51996 to 20250300
Tornadounrated (EFU)1996 to 20250300

The bands show how often events of each severity were recorded in this county, to profile how severe events have been (FEMA's probability item asks for the range of intensities).

Hail smaller than 1 inch is not counted: on 2010-01-05 the National Weather Service raised its severe-hail threshold from 3/4 inch to 1 inch, so smaller reports became less common after 2009 (NWS Service Change Notice 09-52). NRI hail frequency uses a 0.75 inch threshold.

Optional: future conditions. Not a required item in the 2025 FEMA Local Mitigation Planning Policy Guide; some states ask for it. The federal Climate Mapping for Resilience and Adaptation (CMRA) site gives county exposure to future climate conditions (https://resilience.climate.gov/).

Supports FEMA checklist item B1-f: hazards that vary across jurisdictions

Range of census tract risk within the county

Source: 5

HazardTractsrated of allNRI risk score, 0 to 100Tracts by rating
MinMedianMax
Coastal Flooding30 of 15470.691.399.4Very High 2, Relatively High 8, Relatively Moderate 7, Relatively Low 7, Very Low 6, No Rating 124
Cold Wave154 of 15415.729.248.0Relatively Moderate 1, Relatively Low 152, Very Low 1
Drought13 of 15471.482.092.3Relatively Moderate 1, Relatively Low 7, Very Low 5, No Rating 141
Earthquake153 of 15420.255.980.6Relatively Moderate 3, Relatively Low 135, Very Low 15, No Rating 1
Hail154 of 1540.15.316.5Very Low 154
Heat Wave154 of 1541.728.363.0Relatively Moderate 2, Relatively Low 125, Very Low 27
Hurricane154 of 15411.374.983.6Relatively Moderate 28, Relatively Low 125, Very Low 1
Ice Storm154 of 1540.143.589.0Relatively Moderate 31, Relatively Low 81, Very Low 42
Inland Flooding153 of 1541.839.596.6Very High 1, Relatively High 12, Relatively Moderate 44, Relatively Low 72, Very Low 24, No Rating 1
Landslide154 of 15415.366.292.3Relatively Low 14, Very Low 140
Lightning154 of 1540.233.858.4Relatively Moderate 8, Relatively Low 134, Very Low 12
Strong Wind154 of 1540.224.447.4Relatively Low 119, Very Low 35
Tornado154 of 1540.327.846.7Relatively Low 57, Very Low 97
Tsunami0 of 154Insufficient Data 154
Wildfire134 of 15418.739.682.7Relatively Low 7, Very Low 127, No Rating 20
Winter Weather154 of 15410.622.830.6Relatively Low 142, Very Low 12

Drought: Agriculture is all of NRI's expected annual loss for this hazard in the county, so the tract range mostly reflects where crop and livestock value is.

Rated tracts only: No Rating (score 0.0), Not Applicable and Insufficient Data tracts are counted but not used for the minimum, median and maximum.

The score ranks a tract against all U.S. tracts (100 = highest). The rating is FEMA's category for the tract's risk value, computed differently, so the two can disagree.

Frequency data for cold wave, drought, hail, heat wave, ice storm, lightning, strong wind and winter weather are county-wide or coarse (49 km grid or NWS zone), the same for every jurisdiction; the tract range mostly reflects where buildings and people are (crop and livestock value where a line above names agriculture).

Each jurisdiction (starting figures from federal data)

Sources: 1, 3, 4, 6

JurisdictionTypePlan statusRepetitive lossFMA RL and SRL (44 CFR 77.2); repeat-flood, any definitionPublic Assistance to this jurisdictionFEMA records matched by applicant name; federal share obligated, nominal dollarsEvent records naming this placeall years; since its planNotes
Braintree Town cityCityApproved, expires 2029-11-19FMA RL 0, SRL 2; any 18no Public Assistance recorded0 total; 0 since its plan
Franklin Town cityTownExpired on 2026-01-21FMA RL 0, SRL 0; any 5no Public Assistance recorded0 total; 0 since its plan
Quincy cityCityApproved, expires 2030-12-04FMA RL 0, SRL 23; any 201$12,351,814.8421 total; 0 since its planIncludes $1,554,321.40 for declarations not counted as hazard incidents (DR-4496-MA).
Randolph Town cityTownExpired on 2021-09-20FMA RL 0, SRL 0; any 2no Public Assistance recorded0 total; 0 since its plan
Weymouth Town cityTownApproved, expires 2026-11-28FMA RL 0, SRL 8; any 37no Public Assistance recorded0 total; 0 since its plan
Avon townTownApproved, expires 2027-01-10FMA RL 0, SRL 0; any 0$691,952.556 total; 0 since its planIncludes $183,936.42 for declarations not counted as hazard incidents (DR-4496-MA).
Bellingham townTownExpired on 2025-11-03FMA RL 0, SRL 0; any 0$1,042,761.0911 total; 1 since its planIncludes $222,949.13 for declarations not counted as hazard incidents (DR-4496-MA).
Brookline townTownApproved, expires 2028-11-27FMA RL 0, SRL 0; any 3$3,442,032.4719 total; 0 since its planIncludes $668,914.32 for declarations not counted as hazard incidents (DR-4496-MA, EM-3362-MA).
Canton townTownExpired on 2023-06-21FMA RL 0, SRL 0; any 2$2,540,048.244 total; 3 since its planIncludes $271,708.52 for declarations not counted as hazard incidents (DR-4496-MA).
Cohasset townTownExpired on 2025-11-11FMA RL 0, SRL 2; any 10$798,281.495 total; 0 since its planIncludes $267,563.28 for declarations not counted as hazard incidents (DR-4496-MA).
Dedham townTownExpired on 2026-02-23FMA RL 0, SRL 0; any 1$2,377,546.224 total; 1 since its planIncludes $646,948 for declarations not counted as hazard incidents (DR-4496-MA).
Dover townTownApproved, expires 2027-09-25FMA RL 0, SRL 0; any 1$598,123.928 total; 0 since its planIncludes $80,998.84 for declarations not counted as hazard incidents (DR-4496-MA).
Foxborough townTownExpired on 2025-10-14FMA RL 0, SRL 0; any 1$1,215,893.4615 total; 0 since its planIncludes $376,508.34 for declarations not counted as hazard incidents (DR-4496-MA).
Holbrook townTownNo approved plan on recordFMA RL 0, SRL 0; any 5$897,157.849 total; no approved planIncludes $369,848.44 for declarations not counted as hazard incidents (DR-4496-MA).
Medfield townTownExpired on 2024-09-19FMA RL 0, SRL 0; any 0$910,464.628 total; 4 since its planIncludes $119,696.88 for declarations not counted as hazard incidents (DR-4496-MA).
Medway townTownApproved, expires 2030-01-12FMA RL 0, SRL 0; any 1$1,275,385.0818 total; 0 since its planIncludes $221,364.32 for declarations not counted as hazard incidents (DR-4496-MA).
Millis townTownApproved, expires 2030-11-12FMA RL 0, SRL 0; any 1$892,581.773 total; 0 since its planIncludes $81,551.40 for declarations not counted as hazard incidents (DR-4496-MA).
Milton townTownApproved, expires 2027-01-06FMA RL 0, SRL 0; any 7$1,752,109.5819 total; 3 since its planIncludes $541,737.51 for declarations not counted as hazard incidents (DR-4496-MA).
Needham townTownExpired on 2026-01-21FMA RL 0, SRL 0; any 4$2,594,633.1820 total; 2 since its planIncludes $436,628.81 for declarations not counted as hazard incidents (DR-4496-MA).
Norfolk townTownApproved, expires 2029-02-27FMA RL 0, SRL 0; any 5$1,477,646.9711 total; 0 since its planIncludes $718,879.10 for declarations not counted as hazard incidents (DR-4496-MA).
Norwood townTownApproved, expires 2030-09-15FMA RL 0, SRL 0; any 2$2,854,039.446 total; 0 since its planIncludes $725,610.65 for declarations not counted as hazard incidents (DR-4496-MA).
Plainville townTownExpired on 2013-04-02FMA RL 0, SRL 0; any 0$603,516.687 total; 4 since its planIncludes $171,429.67 for declarations not counted as hazard incidents (DR-4496-MA).
Sharon townTownApproved, expires 2030-10-19FMA RL 0, SRL 0; any 1$1,107,280.1313 total; 0 since its planIncludes $204,793.02 for declarations not counted as hazard incidents (DR-4496-MA).
Stoughton townTownApproved, expires 2030-02-11FMA RL 0, SRL 0; any 1$2,190,729.2916 total; 0 since its planIncludes $418,674.79 for declarations not counted as hazard incidents (DR-4496-MA).
Walpole townTownExpired on 2022-05-31FMA RL 0, SRL 0; any 0$1,654,394.0227 total; 2 since its planIncludes $132,630.32 for declarations not counted as hazard incidents (DR-4496-MA).
Wellesley townTownApproved, expires 2029-02-22FMA RL 0, SRL 0; any 6$2,295,743.0218 total; 0 since its planIncludes $910,517.17 for declarations not counted as hazard incidents (DR-4496-MA, EM-3362-MA).
Westwood townTownApproved, expires 2029-04-11FMA RL 0, SRL 0; any 4$1,939,542.199 total; 0 since its planIncludes $385,561.29 for declarations not counted as hazard incidents (DR-4496-MA).
Wrentham townTownExpired on 2023-11-26FMA RL 0, SRL 0; any 0$998,132.1419 total; 4 since its planIncludes $272,473.15 for declarations not counted as hazard incidents (DR-4496-MA).

Repetitive-loss counts are for whole NFIP communities, which can extend beyond this county (see the note in B2-c).

School districts and special districts get a plan clock row only.

County Public Assistance in B1-d also includes applicants filed under the county that are not jurisdictions in this plan (for example state agencies, special districts and nonprofits), so the jurisdiction rows add up to less.

Supports FEMA checklist items B2-a and B2-b: vulnerability and potential impacts

Local data needed

The table below gives county-level starting figures; the plan describes impacts for each jurisdiction and its own assets.

No county-level plan row in FEMA data, so there is no approval date to count from.

  • Critical facilities and lifelines per hazard
  • A problem statement per jurisdiction per hazard
  • Changes in development in hazard-prone areas since the last approval, or a statement of none (E1-a)
  • Future assets

County-level starter: exposure, expected annual loss and damage since the plan

Sources: 1, 2, 3, 5, 6, 7

HazardBuilding exposuremodeled dollarsAgriculture exposuremodeled dollarsPopulation exposedpeopleEAL buildingsmodeled dollars per yearEAL agriculturemodeled dollars per yearCost of expected deaths and injuriesFEMA's dollar value per year, not property damageEAL as % of exposurebuildings; agriculture where notedStorm Events damage since plancounty-coded records, property plus crops, nominal dollarsZone-level damage since planproperty plus crops, reported for the zonePublic Assistance since plannominal dollars; see noteNote
Coastal Flooding$8,996,912,230n/a36,791$5,070,024n/a$20,6210.0564%
Cold Wave$167,152,963,713$6,394,921725,648$2,308$689$3,321,296under 0.0001%
Droughtn/a$5,164,595n/an/a$97,921n/a1.9% (agriculture)NRI has no building exposure for this hazard; agriculture shown
Earthquake$284,229,827,628n/a725,981$7,106,937n/a$1,774,7970.0025%
Hail$167,152,963,713$6,394,921725,648$32,194$44$10,374under 0.0001%
Heat Wave$167,152,963,713$6,394,921725,648$5$914$3,861,543under 0.0001%
Hurricane$167,128,274,976$6,394,921725,420$15,130,182$51,197$446,7680.00905%
Ice Storm$166,532,991,673n/a722,144$1,155,664n/a$35,1160.000694%
Inland Flooding$166,996,668,556$111,20227,330$102,429,843$24$637,899n/a (see note)NRI counts the full building value of any census block with some flood loss; this is not the value of buildings in the floodplain. Use local FIRM overlays for B2-a/B2-b.
Landslide$3,443,873,422n/a14,882$8,740n/a$6360.000254%
Lightning$167,152,963,713n/a725,648$202,168n/a$1,049,6090.000121%
Strong Wind$167,152,963,713$6,394,921725,648$650,411under $1$488,7600.000389%
Tornado$167,152,963,713$6,394,921725,648$2,798,739$65$389,7970.00167%
Tsunamin/an/an/an/an/an/aNRI publishes no building exposure for this county
Wildfire$10,874,924,098$672,17657,147$55,475$1$5,3910.00051%
Winter Weather$167,152,963,713$6,394,921725,648$56,415$3$24,851under 0.0001%

Totals since the plan: not available. No county-level plan row in FEMA data, so there is no approval date to count from.

FEMA does not split Public Assistance by hazard. A declaration mapped to several hazards is listed under each of them with its full amount, so the per-hazard column does not add up to the total; the unit total counts each declaration once.

NRI computes earthquake exposure on its own basis, so it exceeds the county building value in B2-a.

Supports FEMA checklist item B2-a: vulnerability (county context)

County context

Source: 5

MeasureValue
Population725,648
Building value (total, not at risk)$167,152,963,713
Agriculture value (total, not at risk)$6,394,921
NRI risk rating (all hazards)Relatively Moderate
Expected annual loss, buildings and agriculture, all hazards$134,849,962
Expected annual loss, population equivalence, all hazards (NRI values each statistical life at $13.7M; a modeled value of expected deaths and injuries, not property damage)$12,067,457
Social vulnerability ratingVery Low
Community resilience ratingVery High
NRI versionDecember 2025

FEMA's all-hazard expected annual loss adds buildings, agriculture and population equivalence; this table gives the property part and the population-equivalence part as separate rows.

Social vulnerability: higher means people are more likely to be harmed and slower to recover. Community resilience: lower means the community is less able to recover. High social vulnerability and low resilience both raise the NRI risk rating.

Supports FEMA checklist item B2-c: repetitive loss properties

Repetitive loss in this county, both definitions

Sources: 1, 4

DefinitionPropertiesSevere repetitive lossProperties
Repetitive loss, FMA definition (44 CFR 77.2)0Severe repetitive loss, FMA definition (44 CFR 77.2)35
Repetitive loss, NFIP insurance definition317Severe repetitive loss, NFIP insurance definition34

The state NFIP coordinator's list, the source FEMA's Handbook names, often uses the NFIP insurance definition (second row).

Repeat-flood properties: county total and NFIP communities

Sources: 1, 4

ScopeRL, FMApropertiesSRL, FMApropertiesRL, NFIPpropertiesSRL, NFIPpropertiesAny categorypropertiesMitigatedpropertiesCurrently insuredproperties
County total035317343181131
of which: Braintree town021821805
of which: Brookline town0030301
of which: Canton town0020201
of which: Cohasset town02911016
of which: Dedham town0010101
of which: Dover town0010101
of which: Foxborough town0010100
of which: Franklin town0050502
of which: Medway town0010100
of which: Millis town0010100
of which: Milton town0070700
of which: Norwood town0020200
of which: Randolph town0020200
of which: Sharon town0010101
of which: Stoughton town0010100
of which: Wellesley town0060602
of which: Weymouth town0837837018
of which: Holbrook town0050503
of which: Needham town0040402
of which: Norfolk town0050501
of which: Quincy city02320123201087
of which: Westwood town0040400

Repeat-flood properties by jurisdiction in the plan (NFIP community)

Sources: 1, 4

JurisdictionNFIP community IDRL, FMApropertiesSRL, FMApropertiesRL, NFIPpropertiesSRL, NFIPpropertiesAny categorypropertiesMitigatedpropertiesCurrently insuredproperties
Braintree Town city250233021821805
Franklin Town city2502400050502
Quincy city25521902320123201087
Randolph Town city2502510020200
Weymouth Town city2502570837837018
Avon town2502310000000
Bellingham town2502320000000
Brookline town2502340030301
Canton town2502350020201
Cohasset town25023602911016
Dedham town2502370010101
Dover town2502380010101
Foxborough town2502390010100
Holbrook town2552120050503
Medfield town2502420000000
Medway town2502430010100
Millis town2502440010100
Milton town2502450070700
Needham town2552150040402
Norfolk town2552170050501
Norwood town2502480020200
Plainville town2502490000000
Sharon town2502520010101
Stoughton town2502530010100
Walpole town2502540000000
Wellesley town2502550060602
Westwood town2552250040400
Wrentham town2502580000000

Counts by occupancy group for each jurisdiction are in the Excel file, sheet "B2-c Jurisdictions".

Jurisdiction rows are whole NFIP communities and need not add up to the county total: a community that extends into another county is counted in full on each jurisdiction row, while the county table counts only its part in this county.

County repeat-flood properties by occupancy group

Sources: 1, 4

Occupancy groupRL, FMApropertiesSRL, FMApropertiesRL, NFIPpropertiesSRL, NFIPpropertiesAny categorypropertiesMitigatedpropertiesCurrently insuredproperties
single-family residential028262282620107
2 to 4 unit residential0427328114
other residential011111105
non-residential021721705
not reported0000000

FEMA's occupancy groups have no institutional class; institutional properties are counted in non-residential or other residential in the table by occupancy group.

FMA RL and FMA SRL are the Flood Mitigation Assistance definitions (44 CFR 77.2), the ones the FEMA Local Mitigation Planning Policy Guide cites. NFIP repetitive loss (the FEMA insurance definition) is 2 or more claims over $1,000 in 10 years, and a property can leave that group once it is mitigated. Also shown: NFIP severe repetitive loss, any category, mitigated and currently insured. The Methods page gives the OpenFEMA field details.

Counts are aggregates of FEMA's public NFIP Multiple Loss Properties file (FEMA's data date 2026-08-02; file version 2026-08-04). No property is identified. County assignment is FEMA's geocode.

In this county 0 properties are FMA repetitive loss but not NFIP repetitive loss, and 317 properties are NFIP repetitive loss but not FMA repetitive loss.

Exact counts; no count suppression.

Sources

Tables cite these sources by number. The full list, for the plan's bibliography (FEMA review item A4-a):

  1. FEMA, OpenFEMA HazardMitigationPlanStatuses v1, version 2026-09-29T134039Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/HazardMitigationPlanStatuses (API)
  2. FEMA, OpenFEMA DisasterDeclarationsSummaries v2, version 2026-09-29T162832Z, pulled 2026-09-30, https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries (API)
  3. FEMA, OpenFEMA PublicAssistanceFundedProjectsSummaries v1, version 2026-09-29T150754Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/PublicAssistanceFundedProjectsSummaries (API)
  4. FEMA, OpenFEMA NfipMultipleLossProperties v1, version 2026-08-04T164045Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/NfipMultipleLossProperties (API)
  5. FEMA, FEMA National Risk Index 1.20.0 (December 2025), county and census tract tables, version 1.20.0, pulled 2026-09-30, https://www.fema.gov/about/reports-and-data/openfema/nri/v120/NRI_Table_Counties.zip (download, 25 MB), https://www.fema.gov/about/reports-and-data/openfema/nri/v120/NRI_Table_CensusTracts.zip (download, 635 MB)
  6. NOAA NCEI, NOAA NCEI Storm Events Database, details files (csvfiles v1.0), version c20260918, pulled 2026-09-30, https://www.ncei.noaa.gov/pub/data/swdi/stormevents/csvfiles/
  7. NOAA National Weather Service, NWS county-public forecast zones correlation file, version bp03mr20 to bp16ap26 (11 files; newest bp16ap26), pulled 2026-09-30, https://www.weather.gov/gis/ZoneCounty
  8. U.S. Census Bureau, Census 2024 Gazetteer, 2020 place by county, CT county-to-cousub crosswalk, version 2024-gazetteer, pulled 2026-09-30, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_counties_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_cousubs_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_place_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_unsd_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_elsd_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_scsd_national.zip, https://www2.census.gov/geo/docs/reference/codes2020/national_place_by_county2020.txt, https://www2.census.gov/geo/docs/reference/ct_change/ct_cou_to_cousub_crosswalk.xlsx (used to match place names and codes; no table prints its values)

What this packet is and what the plan adds

This packet is the federal data for the plan's risk assessment (the summary on page 1 says how it is organized); the plan and FEMA's review decide whether each item is met.

The plan adds what only the community has: local data on assets, critical facilities, development and each jurisdiction's impacts; local hazard history, including state-declared emergencies; the mitigation strategy; and adoption.

How the federal data are built: National Risk Index values are FEMA's model, not counts of events. Storm Events is more complete from 1996; zone-level records are placed by forecast zone, not by location in the county. Public Assistance for a jurisdiction is matched by applicant name. The Methods page gives every rule and the known edge cases.

OpenFEMA disclaimer

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

Reuse, citation and corrections

Reuse and citation: Hazard Plain text and tables are licensed under Creative Commons Attribution 4.0 International (CC BY 4.0, https://creativecommons.org/licenses/by/4.0/); credit Hazard Plain and the release. The underlying federal data are public domain; OpenFEMA data are also subject to the OpenFEMA terms and conditions.

Cite this: Hazard Plain (2026). Norfolk County, MA: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-30; County FIPS 25021). Automated baseline. https://hazardplain.org/ma/25021/ Built from FEMA OpenFEMA, the FEMA National Risk Index and NOAA NCEI Storm Events; source versions in the packet's Sources list.

Corrections: to report an error, name the packet, the table and what your records show. Contact: contact@hazardplain.org