Hazard Plain Automated baseline

Plymouth County, MA

Risk-assessment baseline packet

County FIPS:
25023
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 ($71,359,326 a year), Coastal Flooding ($14,336,053) and Hurricane ($11,288,030).

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: 27 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 expiryNotes
Bridgewater Town cityTownApproved, expires 2027-08-10Town of Bridgewater, MA Hazard Mitigation Plan (FEMA plan 108263)2022-08-112027-08-10314
Brockton cityCityApproved, expires 2027-12-13Brockton Natural Hazard Mitigation Plan (FEMA plan 108309)2022-12-142027-12-13439this jurisdiction approved 2022-12-09
Abington 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
Carver townTownApproved, expires 2027-06-29Town of Carver Hazard Mitigation Plan 2022 (FEMA plan 108233)2022-06-302027-06-29272
Duxbury townTownExpired on 2024-01-08Town of Duxbury Hazard Mitigation Plan 2018 (FEMA plan 105478)2019-01-092024-01-08-996
East Bridgewater townTownExpired on 2020-11-12Natural Hazard Mitigation Plan for the Old Colony Region May 2015 (FEMA plan 11350)2015-11-122020-11-12-2,148
Halifax townTownApproved, expires 2027-02-13Town of Halifax, Massachusetts Integrated Municipal Vulnerability Preparedness and Hazard Mitigation Plan (MVP-HMP) (FEMA plan 107718)2022-02-142027-02-13136
Hanover townTownApproved, expires 2030-04-15Town of Hanover Hazard Mitigation Plan 2024 Update (FEMA plan 109762)2025-04-162030-04-151,293
Hanson townTownApproved, expires 2027-01-03Town of Hanson, Massachusetts Integrated Municipal Vulnerability Preparedness and Hazard Mitigation Plan (MVP-HMP) (FEMA plan 107611)2022-01-042027-01-0395
Hingham townTownApproved, expires 2027-07-10Town of Hingham Hazard Mitigation Plan 2022 Update (FEMA plan 108265)2022-07-112027-07-10283
Hull townTownApproved, expires 2029-09-12Town of Hull Hazard Mitigation Plan 2024 Update (FEMA plan 109990)2024-09-132029-09-121,078
Kingston townTownApproved, expires 2027-09-01Hazard Mitigation Plan, Kingston, Massachusetts 2022 (FEMA plan 108388)2022-09-022027-09-01336
Lakeville townTownApproved, expires 2027-09-11Town of Lakeville Natural Hazard Mitigation Plan 2022 (FEMA plan 108327)2022-09-122027-09-11346
Marion townTownApproved, expires 2027-01-10Marion Multi-Hazard Mitigation Plan (FEMA plan 107875)2022-01-112027-01-10102
Marshfield townTownApproved, expires 2028-12-12Marshfield Multi-Hazard Mitigation Plan (FEMA plan 109126)2023-12-132028-12-12804
Mattapoisett townTownApproved, expires 2031-01-29Town of Mattapoisett Multi-Hazard Mitigation Plan (FEMA plan 110853)2026-01-302031-01-291,582
Middleborough townTownApproved, expires 2029-04-11Town of Middleborough, MA Hazard Mitigation Plan Update (FEMA plan 109353)2024-04-122029-04-11924
Norwell townTownExpired on 2025-12-03Town of Norwell Hazard Mitigation Plan 2020 Update (FEMA plan 106750)2020-12-042025-12-03-301
Pembroke townTownApproved, expires 2028-02-15Town of Pembroke, MA Municipal Vulnerability & Hazard Mitigation Plan (FEMA plan 108293)2023-02-162028-02-15503
Plymouth townTownApproved, expires 2026-12-152021 Hazard Mitigation Plan Plymouth, Massachusetts (FEMA plan 107852)2021-12-162026-12-1576
Plympton townTownApproved, expires 2026-12-07Plympton Multi-Hazard Mitigation Plan (FEMA plan 107804)2021-12-082026-12-0768
Rochester townTownApproved, expires 2030-07-202024 Hazard Mitigation Plan, Rochester, Massachusetts (FEMA plan 110257)2025-07-212030-07-201,389
Rockland townTownExpired on 2024-08-26Town of Rockland Hazard Mitigation Plan (FEMA plan 105857)2019-08-272024-08-26-765
Scituate townTownApproved, expires 2027-06-292022 Scituate, MA Hazard Mitigation Plan (FEMA plan 108287)2022-06-302027-06-29272
Wareham townTownExpired on 2025-12-20Wareham Multi-Hazard Mitigation Plan (FEMA plan 106824)2020-12-212025-12-20-284
West Bridgewater townTownApproved, expires 2027-11-01Town of West Bridgewater Multi-Hazard Mitigation Plan (FEMA plan 108481)2022-11-022027-11-01397
Whitman townTownApproved, expires 2027-01-06Town of Whitman, Massachusetts Integrated Municipal Vulnerability Preparedness and Hazard Mitigation Plan (MVP-HMP) (FEMA plan 107717)2022-01-072027-01-0698

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 ModerateRelatively High$70,400,283$497,798$461,245$71,359,32681
2Coastal FloodingVery HighVery High$14,314,229n/a$21,828$14,336,05365
3HurricaneRelatively ModerateRelatively High$10,245,702$721,624$320,704$11,288,0306
4EarthquakeRelatively LowRelatively Moderate$4,080,048n/a$779,549$4,859,597Storm Events does not record earthquakes.
5Strong WindRelatively HighRelatively High$1,214,583$200$1,987,355$3,202,139457Includes 105 High Wind and 175 Strong Wind records (NOAA non-thunderstorm wind types, outside NRI's Strong Wind definition).
6Heat WaveRelatively ModerateRelatively Moderate$3$11,003$2,535,218$2,546,2243
7Cold WaveRelatively LowRelatively Moderate$1,293$7,725$1,975,106$1,984,1242
8LightningRelatively HighRelatively High$82,283n/a$1,565,714$1,647,99745
9TornadoRelatively LowRelatively Low$1,319,957$661$220,789$1,541,4073
10DroughtRelatively ModerateRelatively Moderaten/a$690,039n/a$690,0398
11Ice StormRelatively HighRelatively High$620,728n/a$69,107$689,8350No recorded events in Storm Events since 1996 (data through 2026-06-30).
12WildfireVery LowVery Low$69,236$12$8,268$77,5160No recorded events in Storm Events since 1996 (data through 2026-06-30).
13Winter WeatherRelatively LowRelatively Low$39,578$31$20,133$59,742119
14HailVery LowVery Low$19,303$224$7,457$26,98577
15LandslideVery LowVery Low$3,400n/a$566$3,9660No 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 wildfire, 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 9803 (Relatively Moderate, 80.3); tract 5012.04 (Relatively Moderate, 78.0); tract 5041.01 (Relatively Low, 74.7)
Hurricanetract 5411 (Relatively Moderate, 83.4); tract 5422 (Relatively Moderate, 83.1); tract 5012.04 (Relatively Moderate, 83.0)
Landslidetract 5307 (Relatively Low, 91.8); tract 5306 (Relatively Low, 89.7); tract 5308.01 (Relatively Low, 82.5)
Tornadotract 5011.02 (Relatively Low, 38.6); tract 5012.04 (Relatively Low, 37.3); tract 5041.01 (Relatively Low, 35.4)
Tsunamino tract has a National Risk Index rating for this hazard
Wildfiretract 5071.01 (Relatively Low, 77.2); tract 5061.02 (Relatively Low, 75.9); tract 5041.02 (Relatively Low, 75.0)

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 9803 is Census Tract 9803). 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)65 records, 1997 to 2024 (64 zone-level)Coastal Flood, 2013-02-09, $9,200,000 property; $0 crops (2013 dollars); NWS zone MAZ019Event records naming jurisdictions in the plan: Hingham town (1 record). Zone-level records (64) apply countywide.Flood depth: see the FEMA Flood Insurance Rate Map.
Cold/Wind Chill, Extreme Cold/Wind Chillwind chill2 records, 2015 to 2016 (2 zone-level)1 day; 2 with a recorded value1 consecutive day, 2016-02-14, zone-levelCountywide (zone-level records).
Frost/Freeze (outside NRI's Cold Wave definition)crop damage0
DroughtU.S. Drought Monitor scale (D0 to D4)8 records, 2012 to 2017 (8 zone-level)34 days to 155 days (median 94.5 days); 2 with a recorded value155 days (about 5.1 months), 2016-08-23 to 2017-01-24, a run of 6 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, 1959 to 20250.75 in to 2.75 in (median 1 in); 82 with a recorded value2.75 in hail, 1999-07-06Hail, 2004-07-02, $35,000 property; crops not reported (2004 dollars)Event records naming jurisdictions in the plan: Plymouth town (13 records), Brockton city (8 records), Duxbury town (4 records), Scituate town (4 records), Whitman town (4 records), Abington town (3 records), Rockland town (3 records), West Bridgewater town (3 records), Carver town (2 records), Halifax town (2 records); and 14 more jurisdictions (see the Excel file).
Excessive Heat, Heatheat index (in event narratives)3 records, 2010 to 2018 (3 zone-level)1 day; 3 with a recorded value1 consecutive day, 2018-07-03, zone-levelCountywide (zone-level records).
Hurricane, Tropical Storm, Tropical DepressionSaffir-Simpson6 records, 2008 to 2021 (6 zone-level)Strongest recorded: Tropical Storm record, 2011-08-28, $1,600,000 property; $0 crops (2011 dollars); NWS zone MAZ018Countywide (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)81 records, 1996 to 2025 (5 zone-level)Flood, 2010-03-14, $16,150,000 property; $0 crops (2010 dollars)Event records naming jurisdictions in the plan: Hingham town (8 records), Plymouth town (7 records), Marion town (6 records), Brockton city (4 records), Kingston town (3 records), Wareham town (3 records), Whitman town (2 records), Carver town (1 record), East Bridgewater town (1 record), Hanover town (1 record); and 2 more jurisdictions (see the Excel file). Zone-level records (5) 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)45 records, 1996 to 2024Lightning, 2010-09-08, $0 property; $0 crops (2010 dollars), 1 direct deathLightning, 2014-10-08, $300,000 property; $0 crops (2014 dollars)Event records naming jurisdictions in the plan: Hingham town (4 records), Plymouth town (4 records), Brockton city (3 records), Halifax town (3 records), Duxbury town (2 records), Hanover town (2 records), Whitman town (2 records), East Bridgewater town (1 record), Hanson town (1 record), Hull town (1 record); and 9 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)280 records, 1996 to 2025 (280 zone-level)26 kt (30 mph) to 76 kt (87 mph) (median 48 kt (55 mph)); 216 with a recorded value76 kt (87 mph) measured gust, High Wind, 2021-10-26; NWS zone MAZ019Countywide (zone-level records).
Thunderstorm Windwind speed (kt and mph)197 records, 1961 to 202540 kt (46 mph) to 90 kt (104 mph) (median 50 kt (58 mph)); 181 with a recorded value90 kt (104 mph), measurement type not recorded, Thunderstorm Wind, 1997-06-22, 1 direct death; same speed and measurement basis also recorded on 1996-05-21Thunderstorm Wind, 1996-05-21, $4,000,000 property; crops not reported (1996 dollars)Event records naming jurisdictions in the plan: Hingham town (21 records), Plymouth town (10 records), Brockton city (8 records), Whitman town (7 records), Duxbury town (6 records), Pembroke town (6 records), Scituate town (6 records), Halifax town (5 records), Rochester town (5 records), Abington town (3 records); and 11 more jurisdictions (see the Excel file).
TornadoEnhanced Fujita (Fujita before Feb 2007)10 records, 1958 to 2023F/EF0 to F/EF2 (median between F/EF0 and F/EF1); 10 with a recorded valueF2 tornado, 1967-11-18, 0.1 mi path length (whole path, pre-1996), 17 yd wide, $250 property; crops not recorded (1967 dollars)Tornado, 1986-09-16, $250,000 property; crops not recorded (1986 dollars)Event records naming jurisdictions in the plan: Plymouth 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)0
Winter Storm, Heavy Snow, Blizzard, Lake-Effect Snow, Winter Weather, Sleetnone in data (snowfall: local data)119 records, 1996 to 2026 (119 zone-level)Heavy Snow, 1997-04-01, $2,500,000 property; crops not reported (1997 dollars); NWS zone MAZ018Countywide (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: 32 declarations covering 25 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 LeeHurricane$2,954.08within last 5 years
2022-04-182022-01-28DR-4651-MAMajor disasterSevere Winter Storm and SnowstormWinter Weather$3,346,871.88within last 5 years
2020-03-272020-01-20DR-4496-MAMajor disasterCOVID-19 PandemicNon-natural, not counted$26,700,364.80
2020-03-132020-01-20EM-3438-MAEmergencyCOVID-19Non-natural, not countedno Public Assistance recordedsame incident as DR-4496
2018-06-252018-03-02DR-4372-MAMajor disasterSevere Winter Storm and FloodingInland Flooding; Winter Weather$12,430,409.86
2015-04-132015-01-26DR-4214-MAMajor disasterSevere Winter Storm, Snowstorm, and FloodingInland Flooding; Winter Weather$8,118,237.20
2013-04-192013-02-08DR-4110-MAMajor disasterSevere Winter Storm, Snowstorm, and FloodingInland Flooding; Winter Weather$5,327,481.26
2012-12-192012-10-27DR-4097-MAMajor disasterHurricane SandyHurricane$1,268,254.30
2012-10-282012-10-27EM-3350-MAEmergencyHurricane SandyHurricaneno Public Assistance recordedsame incident as DR-4097
2011-09-032011-08-27DR-4028-MAMajor disasterTropical Storm IreneHurricane$2,074,590.38
2011-08-262011-08-26EM-3330-MAEmergencyHurricane IreneHurricaneno Public Assistance recordedsame incident as DR-4028
2010-09-022010-09-01EM-3315-MAEmergencyHurricane EarlHurricane$108,710.03
2010-03-292010-03-12DR-1895-MAMajor disasterSevere Storms and FloodingInland Flooding$975,580.21
2007-05-162007-04-15DR-1701-MAMajor disasterSevere Storms and Inland and Coastal FloodingCoastal Flooding$1,322,878.28
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 counted$11,866.36
2005-02-172005-01-22EM-3201-MAEmergencyRecord and/or Near Record SnowWinter Weather$3,169,511.85
2004-01-152003-12-06EM-3191-MAEmergencySnowWinter Weather$1,816,405.45
2003-03-112003-02-17EM-3175-MAEmergencySnowWinter Weather$1,677,017.59
2001-04-102001-03-05DR-1364-MAMajor disasterSevere Storms and FloodingInland FloodingPA not declared for this county
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
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 Flooding651041996 to 2026-06-30
Cold Wave2001996 to 2026-06-30
Drought8001996 to 2026-06-30
Earthquake000Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hail82601955 to 2026-06-30
Heat Wave3001996 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 Flooding811091996 to 2026-06-30
Landslide0001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Lightning45401996 to 2026-06-30
Strong Wind4776501955 to 2026-06-30Includes 105 High Wind and 175 Strong Wind records.
Tornado10101950 to 2026-06-30
Tsunami0001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Wildfire0001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Winter Weather119891996 to 2026-06-30

Notable Storm Events records

Sources: 1, 6, 7

DateEvent typeMagnitude or extentDamagenominal dollarsDeaths, injuriesdirect onlyLocationFlagsWhy listed
2023-12-18Strong Wind43 kt (49 mph) measured gust$0 property; $0 crops (zone total, 2023 dollars)1, 0NWS zone MAZ018 (WESTERN PLYMOUTH), zone-levelwithin last 5 yearsdeaths or injuries recorded
2021-10-26High Wind76 kt (87 mph) measured gust$1,660,000 property; $0 crops (zone total, 2021 dollars)0, 0NWS zone MAZ019 (EASTERN PLYMOUTH), zone-levelwithin last 5 yearsB1-c worst recorded: High Wind and Strong Wind
2018-07-03Excessive Heat$0 property; $0 crops (zone total, 2018 dollars)0, 0NWS zone MAZ019 (EASTERN PLYMOUTH), zone-levelB1-c worst recorded: Excessive Heat, Heat
2016-04-03Strong Wind43 kt (49 mph) estimated gust$15,000 property; $0 crops (zone total, 2016 dollars)2, 0NWS zone MAZ018 (WESTERN PLYMOUTH), zone-leveldeaths or injuries recorded
2016-02-14Extreme Cold/Wind Chill$0 property; $0 crops (zone total, 2016 dollars)0, 0NWS zone MAZ019 (EASTERN PLYMOUTH), zone-levelB1-c worst recorded: Cold/Wind Chill, Extreme Cold/Wind Chill
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$1,600,000 property; $0 crops (zone total, 2011 dollars)0, 0NWS zone MAZ018 (WESTERN PLYMOUTH), zone-levelB1-c worst recorded: Hurricane, Tropical Storm, Tropical Depression
2010-09-08Lightning$0 property; $0 crops (2010 dollars)1, 0PLYMOUTHB1-c worst recorded: Lightning
2010-03-14Flood$16,150,000 property; $0 crops (2010 dollars)0, 0HANOVER to COCHESETTB1-c worst recorded: Flash Flood, Flood, Lakeshore Flood
1997-06-22Thunderstorm Wind90 kt (104 mph), measurement type not recordeddamage not reported1, 0HULLB1-c worst recorded: Thunderstorm Wind
1967-11-18TornadoF2, 0.1 mi path length (whole path, pre-1996), 17 yd wide$250 property; crops not recorded (1967 dollars)0, 0location not recordedB1-c worst recorded: Tornado
1958-09-07TornadoF0, 33 yd wide$2,500 property; crops not recorded (1958 dollars)1, 1location not recordeddeaths or injuries recorded

The full list is in the Excel file, sheet "B1-d Storm Events history" (898 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 Flooding7.14events per year at a location (modeled)about 7.1 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 Wave1.03event-days per yearabout 1.03 days per yearPossibleStorm Events event-days in 2 of 30 years, 1996 to 2025 (6.67%)12.42005-11-12 to 2024-11-12 (19 years)countywide
Drought3.15event-days per yearabout 3.15 days per yearLikelyStorm Events event-days in 3 of 30 years, 1996 to 2025 (10%)2032000 to 2025 (25.25 years; D3 and D4 only)countywide
Earthquake0.00145annual probability at a locationchance a given location in the county has at least minor-damage shaking in a year: 0.145%not shownmodeledsee B1-fNo descriptor (Storm Events does not record earthquakes).
Hail1.28events per yearabout 1.28 per yearHighly likelyFEMA annualized frequency (modeled)55.1 (modeled)1986 to 2023 (38 years)countywide
Heat Wave5.09event-days per yearabout 5.09 days per yearLikelyStorm Events event-days in 3 of 30 years, 1996 to 2025 (10%)53.52005-11-12 to 2024-11-12 (19 years)countywide
Hurricane0.174events 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 Storm0.618event-days per yearabout 0.618 days per yearStorm Events event-days in 0 of 30 years, 1996 to 2025 (0%)311946-12-31 to 2014-02-12 (67 years)countywideNo Storm Events ice storm record, 1996 to 2025
Inland Flooding2.32event-days per yearabout 2.32 days per yearLikelyStorm Events event-days in 25 of 30 years, 1996 to 2025 (83.3%)651996 to 2023 (28 years)see B1-f
Landslide0.191events per year (modeled)about 1 in 5 yearsLikelyFEMA annualized frequency (modeled)not shownmodeledsee B1-f
Lightning18.7days per year with a strikeabout 18.7 days per yearHighly likelyFEMA annualized frequency (modeled)not shown1995 to 2023 (29 years; CONUS)countywide
Strong Wind0.659events per yearabout 0.66 per yearLikelyFEMA annualized frequency (modeled)181986 to 2023 (38 years)countywide
Tornado0.144events per yearabout 1 in 7 yearsLikelyFEMA 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
Wildfire0.0000509annual probability at a locationchance a given location in the county burns in a year: 0.00509%Storm Events records in 0 of 30 years, 1996 to 2025 (0%)not shownmodeledsee B1-fNo descriptor: no Storm Events record 1996 to 2025
Winter Weather11.1event-days per yearabout 11.1 days per yearHighly likelyStorm Events event-days in 27 of 30 years, 1996 to 2025 (90%)1342005-11-12 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 202536301.2
Hail2.00 in+1996 to 20254300.133
Thunderstorm Wind (counted as NRI Strong Wind)50-64 kt1996 to 2025159305.3
Thunderstorm Wind (counted as NRI Strong Wind)65 kt+1996 to 20254300.133
Thunderstorm Wind (counted as NRI Strong Wind)unmeasured or below 50 kt1996 to 202514300.467
TornadoEF0-11996 to 20253300.1
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 Flooding41 of 11070.396.399.9Very High 2, Relatively High 24, Relatively Moderate 6, Relatively Low 3, Very Low 6, No Rating 69
Cold Wave110 of 11019.927.138.1Relatively Low 110
Drought67 of 11068.981.095.2Relatively Moderate 6, Relatively Low 33, Very Low 28, No Rating 43
Earthquake110 of 11021.948.780.3Relatively Moderate 2, Relatively Low 73, Very Low 35
Hail110 of 1101.24.414.7Very Low 110
Heat Wave110 of 1105.925.852.3Relatively Low 82, Very Low 28
Hurricane110 of 11057.274.083.4Relatively Moderate 26, Relatively Low 84
Ice Storm110 of 1108.746.782.1Relatively Moderate 5, Relatively Low 83, Very Low 22
Inland Flooding110 of 1100.838.889.8Relatively High 6, Relatively Moderate 35, Relatively Low 53, Very Low 16
Landslide110 of 11014.354.091.8Relatively Low 3, Very Low 107
Lightning110 of 11022.351.674.5Relatively Moderate 61, Relatively Low 49
Strong Wind110 of 11026.058.279.7Relatively Moderate 67, Relatively Low 43
Tornado110 of 1104.422.738.6Relatively Low 14, Very Low 96
Tsunami0 of 110Insufficient Data 110
Wildfire105 of 11018.549.777.2Relatively Low 10, Very Low 95, No Rating 5
Winter Weather110 of 11016.122.730.9Relatively Low 97, Very Low 13

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
Bridgewater Town cityTownApproved, expires 2027-08-10FMA RL 0, SRL 0; any 2no Public Assistance recorded0 total; 0 since its plan
Brockton cityCityApproved, expires 2027-12-13FMA RL 0, SRL 2; any 40$2,813,814.1023 total; 1 since its plan
Abington townTownApproved, expires 2030-02-11FMA RL 0, SRL 0; any 0$553,189.166 total; 0 since its plan
Carver townTownApproved, expires 2027-06-29FMA RL 0, SRL 0; any 1$808,800.893 total; 0 since its plan
Duxbury townTownExpired on 2024-01-08FMA RL 1, SRL 13; any 66$4,627,285.8412 total; 1 since its planIncludes $32,740.37 for declarations not counted as hazard incidents (DR-4496-MA).
East Bridgewater townTownExpired on 2020-11-12FMA RL 0, SRL 0; any 1$570,170.995 total; 2 since its plan
Halifax townTownApproved, expires 2027-02-13FMA RL 0, SRL 0; any 0$356,914.7110 total; 1 since its plan
Hanover townTownApproved, expires 2030-04-15FMA RL 0, SRL 0; any 0$2,529,295.368 total; 0 since its planIncludes $1,750,066.07 for declarations not counted as hazard incidents (DR-4496-MA).
Hanson townTownApproved, expires 2027-01-03FMA RL 0, SRL 0; any 0$473,322.285 total; 0 since its plan
Hingham townTownApproved, expires 2027-07-10FMA RL 0, SRL 3; any 10$4,245,986.5335 total; 1 since its planIncludes $2,383,064.87 for declarations not counted as hazard incidents (DR-4496-MA).
Hull townTownApproved, expires 2029-09-12FMA RL 2, SRL 34; any 259$2,484,044.886 total; 0 since its planIncludes $84,842.28 for declarations not counted as hazard incidents (DR-4496-MA).
Kingston townTownApproved, expires 2027-09-01FMA RL 0, SRL 0; any 0$698,603.884 total; 0 since its planIncludes $8,105.14 for declarations not counted as hazard incidents (EM-3252-MA).
Lakeville townTownApproved, expires 2027-09-11FMA RL 0, SRL 0; any 2$416,084.294 total; 0 since its plan
Marion townTownApproved, expires 2027-01-10FMA RL 0, SRL 0; any 6$437,398.8111 total; 1 since its plan
Marshfield townTownApproved, expires 2028-12-12FMA RL 6, SRL 44; any 186$4,939,988.693 total; 0 since its plan
Mattapoisett townTownApproved, expires 2031-01-29FMA RL 0, SRL 0; any 10$312,000.663 total; 0 since its plan
Middleborough townTownApproved, expires 2029-04-11FMA RL 0, SRL 0; any 1$872,231.970 total; 0 since its plan
Norwell townTownExpired on 2025-12-03FMA RL 0, SRL 0; any 1$496,908.045 total; 0 since its plan
Pembroke townTownApproved, expires 2028-02-15FMA RL 0, SRL 0; any 0$632,285.849 total; 0 since its plan
Plymouth townTownApproved, expires 2026-12-15FMA RL 2, SRL 7; any 45$1,720,441.9335 total; 2 since its plan
Plympton townTownApproved, expires 2026-12-07FMA RL 0, SRL 0; any 0$164,018.852 total; 0 since its plan
Rochester townTownApproved, expires 2030-07-20FMA RL 0, SRL 0; any 0$410,391.967 total; 0 since its plan
Rockland townTownExpired on 2024-08-26FMA RL 0, SRL 0; any 0$971,083.855 total; 1 since its planIncludes $65,692 for declarations not counted as hazard incidents (DR-4496-MA).
Scituate townTownApproved, expires 2027-06-29FMA RL 18, SRL 171; any 537$8,270,744.5112 total; 1 since its plan
Wareham townTownExpired on 2025-12-20FMA RL 0, SRL 3; any 21$1,078,613.484 total; 0 since its plan
West Bridgewater townTownApproved, expires 2027-11-01FMA RL 0, SRL 0; any 0$421,918.506 total; 0 since its plan
Whitman townTownApproved, expires 2027-01-06FMA RL 0, SRL 0; any 1$347,098.8315 total; 0 since its plan

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

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$8,567,076,367n/a35,642$14,314,229n/a$21,8280.167%
Cold Wave$115,081,264,762$92,622,203530,320$1,293$7,725$1,975,106under 0.0001%
Droughtn/a$71,289,181n/an/a$690,039n/a0.968% (agriculture)NRI has no building exposure for this hazard; agriculture shown
Earthquake$195,481,701,179n/a530,819$4,080,048n/a$779,5490.00209%
Hail$115,081,264,762$92,622,203530,320$19,303$224$7,457under 0.0001%
Heat Wave$115,081,264,762$92,622,203530,320$3$11,003$2,535,218under 0.0001%
Hurricane$115,079,871,287$92,622,203530,307$10,245,702$721,624$320,7040.0089%
Ice Storm$113,214,701,823n/a522,092$620,728n/a$69,1070.000548%
Inland Flooding$114,879,203,462$23,971,76830,563$70,400,283$497,798$461,245n/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$1,922,568,645n/a8,074$3,400n/a$5660.000177%
Lightning$115,081,264,762n/a530,320$82,283n/a$1,565,714under 0.0001%
Strong Wind$115,081,264,762$92,622,203530,320$1,214,583$200$1,987,3550.00106%
Tornado$115,081,264,762$92,622,203530,320$1,319,957$661$220,7890.00115%
Tsunamin/an/an/an/an/an/aNRI publishes no building exposure for this county
Wildfire$15,817,615,588$31,261,76089,492$69,236$12$8,2680.000438%
Winter Weather$115,081,264,762$92,622,203530,320$39,578$31$20,133under 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
Population530,320
Building value (total, not at risk)$115,081,264,762
Agriculture value (total, not at risk)$92,622,203
NRI risk rating (all hazards)Relatively Moderate
Expected annual loss, buildings and agriculture, all hazards$104,339,943
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)$9,973,041
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)29Severe repetitive loss, FMA definition (44 CFR 77.2)277
Repetitive loss, NFIP insurance definition1,162Severe repetitive loss, NFIP insurance definition242

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 total292771,1622421,19127649
of which: Bridgewater town0020200
of which: Brockton city0240240017
of which: Carver town0010100
of which: Duxbury town113651166042
of which: East Bridgewater town0010100
of which: Hingham town031031002
of which: Hull town234258322591144
of which: Lakeville town0020201
of which: Marshfield town644180381866100
of which: Middleborough town0010100
of which: Norwell town0010100
of which: Plymouth town2744645112
of which: Scituate town1817151714753719324
of which: Whitman town0010100
of which: Marion town0060601
of which: Mattapoisett town001001002
of which: Wareham town032132104
of which: Unknown (community ID Unknown in FEMA data)0020200

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

Sources: 1, 4

JurisdictionNFIP community IDRL, FMApropertiesSRL, FMApropertiesRL, NFIPpropertiesSRL, NFIPpropertiesAny categorypropertiesMitigatedpropertiesCurrently insuredproperties
Bridgewater Town city2502600020200
Brockton city2502610240240017
Abington town2502590000000
Carver town2502620010100
Duxbury town250263113651166042
East Bridgewater town2502640010100
Halifax town2502650000000
Hanover town2502660000000
Hanson town2502670000000
Hingham town250268031031002
Hull town250269234258322591144
Kingston town2502700000000
Lakeville town2502710020201
Marion town2552130060601
Marshfield town250273644180381866100
Mattapoisett town255214001001002
Middleborough town2502750010100
Norwell town2502760010100
Pembroke town2502770000000
Plymouth town2502782744645112
Plympton town2502790000000
Rochester town2502800000000
Rockland town2502810000000
Scituate town2502821817151714753719324
Wareham town255223032132104
West Bridgewater town2502840000000
Whitman town2502850010100

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 residential272451,0492141,07423608
2 to 4 unit residential21051853222
other residential0817718111
non-residential01445134618
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 9 properties are FMA repetitive loss but not NFIP repetitive loss, and 1,142 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). Plymouth County, MA: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-30; County FIPS 25023). Automated baseline. https://hazardplain.org/ma/25023/ 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