Hazard Plain Automated baseline

Marin County, CA

Risk-assessment baseline packet

County FIPS:
06041
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: Approved, expires 2029-01-30. Plan: Marin County (FEMA plan 109560), approved 2024-01-31.

Since the plan was approved on 2024-01-31: no new federal declaration.

NOAA Storm Events records since that date: 45 records (data through 2026-06-30).

Highest expected annual loss (FEMA National Risk Index, modeled total; see B1-a): Inland Flooding ($116,012,090 a year), Earthquake ($109,667,898) and Coastal Flooding ($19,783,282).

Repetitive-loss flood properties now: FMA RL 4, SRL 30 (44 CFR 77.2); any definition: 235.

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

Status:
Approved, expires 2029-01-30
Plan:
Marin County (FEMA plan 109560)
Approved:
2024-01-31
Days to expiry:
853

What changed since your last plan (approved 2024-01-31)

New federal declarations:
none
Storm Events records since approval:
45 records (data through 2026-06-30)
Repetitive loss now:
FMA RL 4, SRL 30 (44 CFR 77.2); any definition: 235
Repeat-flood change:
this release sets the baseline count.

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

Plan status for every jurisdiction listed in this county: 18 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
Marin CountyCountyApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-03-22
Belvedere cityCityApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-09-19
Corte Madera townTownApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853
Fairfax townTownApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-07-16
Larkspur cityCityApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-09-23
Mill Valley cityCityApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-09-19
Novato cityCityApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-09-19
Ross townTownApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-08-12
San Anselmo townTownApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-09-19
San Rafael cityCityApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-10-23
Sausalito cityCityApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-04-22
Tiburon townTownApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-07-24
Bolinas Community Public Utility DistrictElectric/Power AuthorityApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-07-22
Las Gallinas Valley Sanitary DistrictWater/Sewer AuthorityApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-09-30
Marin County Transit DistrictSpecial DistrictApproved, expires 2027-11-09Metropolitan Transportation Commission (FEMA plan 110161)2022-11-102027-11-09405this jurisdiction approved 2024-09-03
Marin Municipal Water DistrictWater/Sewer AuthorityApproved, expires 2027-03-20Marin Municipal Water District (FEMA plan 107927)2022-03-212027-03-20171
North Marin Water DistrictWater/Sewer AuthorityApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-07-18
Southern Marin Fire Protection DistrictFire/EMS DistrictApproved, expires 2029-01-30Marin County (FEMA plan 109560)2024-01-312029-01-30853this jurisdiction approved 2024-10-23

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 2026-06-30countWhy this hazard can be left outNRI Not Applicable, no declaration and no Storm Events record since 1996Storm Events coverage note
1Inland FloodingRelatively HighRelatively High$115,135,489$315,166$561,435$116,012,090114
2EarthquakeRelatively HighRelatively High$83,866,586n/a$25,801,313$109,667,898Storm Events does not record earthquakes.
3Coastal FloodingVery HighVery High$19,709,910n/a$73,378$19,783,28227
4TsunamiRelatively ModerateRelatively Moderate$6,374,117n/a$0$6,374,1170No recorded events in Storm Events since 1996 (data through 2026-06-30).
5WildfireRelatively ModerateRelatively Moderate$3,460,593$1,063$154,697$3,616,35323
6LandslideRelatively HighRelatively High$783,700n/a$1,130,250$1,913,95031
7Heat WaveRelatively LowRelatively Low$69$327$1,300,244$1,300,63922
8TornadoVery LowVery Low$180,823$86$61,554$242,4641
9DroughtRelatively LowRelatively Lown/a$183,012n/a$183,0120Declared 1 time; no Storm Events record of this type.
10LightningRelatively LowRelatively Low$7,957n/a$138,348$146,3052
11Strong WindVery LowVery Low$45,791$8$50,207$96,006186Includes 61 High Wind and 121 Strong Wind records (NOAA non-thunderstorm wind types, outside NRI's Strong Wind definition).
12HailVery LowVery Low$6,571$531$1,556$8,65812
13Winter WeatherVery LowVery Low$56under $1$3,060$3,1162
14Volcanic ActivityVery LowVery Lowunder $1n/a$56$560No recorded events in Storm Events since 1996 (data through 2026-06-30).
15Cold WaveNo RatingNo Expected Annual Losses$0$0$0$012Includes 10 Frost/Freeze records (outside NRI's Cold Wave definition; counted in this table and in B1-d, not in the B1-e descriptor).
HurricaneNot ApplicableNot Applicable0NRI rates hurricane Not Applicable for this county, and no counted federal declaration for this county names it (EM-3248-CA names it but is not counted as a local occurrence; see B1-d).No recorded events in Storm Events since 1996 (data through 2026-06-30).
Ice StormNot ApplicableNot Applicable0Declared 1 time; no Storm Events record of this type.

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 tsunami and volcanic activity 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. 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 1122.02 (Very High, 99.6); tract 1121 (Very High, 98.8); tract 1110.02 (Very High, 98.6)
Hurricaneno tract has a National Risk Index rating for this hazard
Landslidetract 1330 (Very High, 99.9); tract 1322 (Relatively High, 99.9); tract 1311 (Relatively High, 99.8)
Tornadotract 1122.02 (Very Low, 18.4); tract 1101 (Very Low, 17.4); tract 1102 (Very Low, 16.8)
Tsunamitract 1302.04 (Relatively Moderate, 93.0); tract 1122.02 (Relatively Moderate, 92.3); tract 1321 (Relatively Moderate, 91.0)
Volcanic Activitytract 1031 (Very Low, 73.4); tract 1101 (Very Low, 72.5); tract 1041.02 (Very Low, 72.0)
Wildfiretract 1330 (Very High, 99.3); tract 1031 (Relatively High, 97.5); tract 1130 (Relatively High, 97.2)

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 1122.02 is Census Tract 1122.02). 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)27 records, 2005 to 2026 (27 zone-level)Coastal Flood, 2005-12-31, $340,000 property; crops not reported (2005 dollars); NWS zone CAZ505Countywide (zone-level records).Flood depth: see the FEMA Flood Insurance Rate Map.
Cold/Wind Chill, Extreme Cold/Wind Chillwind chill2 records, 2013 to 2017 (2 zone-level)1 day; 2 with a recorded value1 consecutive day, 2017-04-08, zone-levelCountywide (zone-level records).Wind chill: in event narratives only (local data needed).
Frost/Freeze (outside NRI's Cold Wave definition)crop damage10 records, 2007 to 2023 (10 zone-level)Frost/Freeze, 2007-01-06, $3,000,000 crop damage (2007 dollars); NWS zone CAZ506Countywide (zone-level records).Temperature: in event narratives only (local data needed).
DroughtU.S. Drought Monitor scale (D0 to D4)0Storm 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)12 records, 1996 to 20210.25 in; 11 with a recorded value0.25 in hail, 2021-03-10; same size also recorded on 2017-11-04, 2018-01-25, 2018-03-02, 2018-03-03, 2018-03-17, 2018-04-16, 2019-12-25, 2020-03-25, 2020-08-17Hail, 2019-12-25, $500 property; $0 crops (2019 dollars)Event records naming jurisdictions in the plan: Corte Madera town (2 records), San Rafael city (2 records), Sausalito city (2 records), Ross town (1 record).
Excessive Heat, Heatheat index (in event narratives)22 records, 2006 to 2026 (22 zone-level)1 day to 6 days (median 1 day); 14 with a recorded value6 consecutive days, 2024-10-02 to 2024-10-07, zone-levelHeat, 2023-07-16, $0 property; $10 crops, reported for the zone (2023 dollars)Countywide (zone-level records).Heat index: in event narratives only (local data needed). 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-Simpson0Storm 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)0Ice thickness: in event narratives only (local data needed).
Flash Flood, Flood, Lakeshore Flooddamage and flood days (flood depth: FIRM)114 records, 1997 to 2025Flood, 2006-01-01, $108,000,000 property; crops not reported (2006 dollars)Event records naming jurisdictions in the plan: Larkspur city (7 records), Corte Madera town (3 records), Novato city (3 records), San Anselmo town (2 records), San Rafael city (2 records), Fairfax town (1 record), Ross town (1 record).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)31 records, 2006 to 2021 (7 zone-level)Debris Flow, 2006-04-01, $14,400,000 property; $20,000,000 crops (2006 dollars), 1 direct death (reported for the zone); NWS zone CAZ506Event records naming jurisdictions in the plan: Sausalito city (7 records), Larkspur city (1 record). Zone-level records (7) apply countywide.Physical measure: in event narratives only (local data needed).
Lightningannualized frequency (the measure FEMA's Local Mitigation Planning Handbook names)2 records, 2009 to 2019Lightning, 2009-09-12, $30,000 property; $0 crops (2009 dollars)No event record names a jurisdiction in the plan.Storm Events lists lightning with damage or casualties; physical measure in event narratives only (local data needed).
High Wind and Strong Wind (outside NRI's Strong Wind definition)wind speed (kt and mph)182 records, 2005 to 2026 (182 zone-level)22 kt (25 mph) to 94 kt (108 mph) (median 45 kt (52 mph)); 177 with a recorded value94 kt (108 mph) measured gust, High Wind, 2025-12-24; NWS zone CAZ502Strong Wind, 2006-12-27, $500,000 property; $0 crops, reported for the zone (2006 dollars)Countywide (zone-level records).Speeds under 20 kt (likely entry errors) are left out of the observed range.
Thunderstorm Windwind speed (kt and mph)4 records, 2004 to 202550 kt (58 mph) to 78 kt (90 mph) (median 60.5 kt (70 mph)); 4 with a recorded value78 kt (90 mph) measured gust, Thunderstorm Wind, 2025-12-25Event records naming jurisdictions in the plan: Sausalito city (1 record).
TornadoEnhanced Fujita (Fujita before Feb 2007)1 record, 1996F/EF1; 1 with a recorded valueF1 tornado, 1996-12-23, 6 mi within this county, 20 yd wide, $200,000 property; $5,000 crops (1996 dollars)No event record names a jurisdiction in the plan.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)0Physical measure: in event narratives only (local data needed).
Volcanic Ash, Volcanic AshfallVolcanic Explosivity Index (local data)0Physical measure: in event narratives only (local data needed).
Wildfireacres burned (local data)23 records, 2013 to 2024 (23 zone-level)Wildfire, 2013-05-01, $500,000 property; $0 crops (2013 dollars); NWS zone CAZ507Countywide (zone-level records).Acres burned: in event narratives only (local data needed).
Winter Storm, Heavy Snow, Blizzard, Lake-Effect Snow, Winter Weather, Sleetnone in data (snowfall: local data)2 records, 2006 to 2011 (2 zone-level)No damage reported in 2 records.Countywide (zone-level records).Snow depth: in event narratives only (local data needed).

Storm Events records are more complete after 1996; before 1996 only Tornado (from 1950), Hail and Thunderstorm Wind (from 1955) exist. Zone-level records whose zone 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: 26 declarations covering 22 separate hazard incidents counted in this packet (declarations for the same incident count once; non-natural and evacuation-only declarations are not counted).

Federal disaster declarations for this county

Sources: 1, 2, 3

DeclaredIncident beganFEMA numberTypeTitleMapped hazardCounty Public Assistancefederal share obligated, nominal dollarsFlagsNotes
2023-04-032023-02-21DR-4699-CAMajor disasterSevere Winter Storms, Straight-Line Winds, Flooding, Landslides, and MudslidesIce Storm; Inland Flooding; Landslide; Strong Wind; Winter Weather$1,043,154.35in the 12 months before plan approval; within last 5 years
2023-01-142022-12-27DR-4683-CAMajor disasterSevere Winter Storms, Flooding, Landslides, and MudslidesInland Flooding (primary); also designated: Landslide, Winter Weather$1,915,579.25within last 5 years
2023-01-092023-01-08EM-3591-CAEmergencySevere Winter Storms, Flooding, and MudslidesInland Flooding (primary); also designated: Landslide, Winter Weatherno Public Assistance recordedwithin last 5 yearssame incident as DR-4683
2020-03-222020-01-20DR-4482-CAMajor disasterCOVID-19 PandemicNon-natural, not counted$38,113,244.59
2020-03-132020-01-20EM-3428-CAEmergencyCOVID-19Non-natural, not countedno Public Assistance recordedsame incident as DR-4482
2019-05-172019-02-24DR-4434-CAMajor disasterSevere Winter Storms, Flooding, Landslides, and MudslidesInland Flooding; Landslide; Winter Weather$319,460.10
2019-05-012019-02-13DR-4431-CAMajor disasterSevere Winter Storms, Flooding, Landslides, and MudslidesInland Flooding; Landslide; Winter Weather$1,935,611.28
2017-04-012017-02-01DR-4308-CAMajor disasterSevere Winter Storms, Flooding, and MudslidesInland Flooding (primary); also designated: Landslide, Winter Weather$2,943,087.60
2017-02-142017-01-03DR-4301-CAMajor disasterSevere Winter Storms, Flooding, and MudslidesInland Flooding; Landslide; Winter Weather$3,809,032.93
2006-06-052006-03-29DR-1646-CAMajor disasterSevere Storms, Flooding, Landslides, and MudslidesInland Flooding; Landslide$3,066,789.36
2006-02-032005-12-17DR-1628-CAMajor disasterSevere Storms, Flooding, Mudslides, and LandslidesInland Flooding; Landslide$10,238,711.78
2005-09-132005-08-29EM-3248-CAEmergencyHurricane Katrina EvacuationHurricane: evacuation support, not a local hazard event; not countedno Public Assistance recorded
1998-02-091998-02-02DR-1203-CAMajor disasterSevere Winter Storms and FloodingInland Flooding; Winter Weatherno Public Assistance recorded
1997-01-041996-12-28DR-1155-CAMajor disasterSevere Storms, Flooding, Mud and LandslidesInland Flooding; Landslideno Public Assistance recorded
1995-03-121995-02-13DR-1046-CAMajor disasterSevere Winter Storms, Flooding Landslides, Mud FlowInland Flooding; Landslide; Winter Weatherno Public Assistance recorded
1995-01-101995-01-03DR-1044-CAMajor disasterSevere Winter Storms, Flooding, Landslides, Mud FlowsInland Flooding; Landslide; Winter Weatherno Public Assistance recorded
1991-02-111990-12-19DR-894-CAMajor disasterSevere FreezeCold WavePA not declared for this county
1989-10-181989-10-17DR-845-CAMajor disasterLoma Prieta EarthquakeEarthquakeno Public Assistance recorded
1986-02-211986-02-12DR-758-CAMajor disasterSevere Storms & FloodingInland Floodingno Public Assistance recorded
1983-02-091983-01-21DR-677-CAMajor disasterCoastal Storms, Floods, Slides & TornadoesCoastal Flooding; Inland Flooding; Landslide; Tornadono Public Assistance recorded
1982-01-071981-12-19DR-651-CAMajor disasterSevere Storms, Flood, Mudslides & High TideInland Flooding (primary); also designated: Landslideno Public Assistance recorded
1977-01-201977-01-20EM-3023-CAEmergencyDroughtDroughtno Public Assistance recorded
1973-02-081973-02-08DR-364-CAMajor disasterSevere Storms, High Tides & FloodingInland Flooding (primary); also designated: Coastal Floodingno Public Assistance recorded
1970-02-161970-02-16DR-283-CAMajor disasterSevere Storms & FloodingInland Floodingno Public Assistance recorded
1969-01-261969-01-26DR-253-CAMajor disasterSevere Storms & FloodingInland Floodingno Public Assistance recorded
1964-12-241964-12-24DR-183-CAMajor disasterHeavy Rains & FloodingInland Floodingno Public Assistance recorded

School districts and special districts in this county: $1,890,005.91 (included in the county total above). Public Assistance matched by applicant name to the school districts and special districts FEMA lists as plan participants in this county. They have no row of their own in the jurisdiction table, so their total is listed here. These dollars are already included in the county PA column of the declarations table (the FEMA record places each applicant in this county), so this line is not added to it.

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
1964-04-011964-04-01DR-169-CAMajor disasterSeismic Sea WaveTsunami
1963-12-211963-12-21DR-161-CAMajor disasterFlood Due to Broken DamOther, not an NRI hazard; not counted
1963-02-251963-02-25DR-145-CAMajor disasterSevere Storms, Heavy Rains & FloodingInland Flooding
1962-10-241962-10-24DR-138-CAMajor disasterSevere Storms & FloodingInland Flooding
1962-03-061962-03-06DR-122-CAMajor disasterFloodsInland Flooding
1961-11-161961-11-16DR-119-CAMajor disasterFire (Los Angeles County)Wildfire
1958-04-041958-04-04DR-82-CAMajor disasterHeavy Rainstorms & FloodInland Flooding
1956-12-291956-12-29DR-65-CAMajor disasterForest FireWildfire
1955-12-231955-12-23DR-47-CAMajor disasterFloodInland Flooding
1954-02-051954-02-05DR-15-CAMajor disasterFlood & ErosionInland Flooding

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.

5 Fire Management declarations (1977-08-07 to 1988-09-13) FEMA filed as Statewide with no county; each names one local fire. Listed on the state page.

Public Assistance filed under this county for declarations that do not list it: 2 rows, $44,496.59

Sources: 2, 3

FEMA numberDeclaredTitleApplicantPA obligatedfederal share obligated, nominal dollars
DR-4344-CA2017-10-10WildfiresSonoma-Marin Area Rail Transit District$36,185.19
DR-4193-CA2014-09-11EarthquakeNorth Coast Railroad Authority$8,311.40

FEMA's Public Assistance summaries file these applicants under this county, but FEMA's declaration rows for these disasters do not designate it (an electric cooperative or district serving several counties, for example). Not in any declaration row above and not counted.

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 Flooding27519201996 to 2026-06-30
Cold Wave12001101996 to 2026-06-30Includes 10 Frost/Freeze records.
Drought0000101996 to 2026-06-30No Storm Events records of this type; 1 federal declared incident (see declarations table)
Earthquake000010Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hail12000001955 to 2026-06-30
Heat Wave226213001996 to 2026-06-30
Hurricane0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Ice Storm0000101996 to 2026-06-30No Storm Events records of this type; 1 federal declared incident (see declarations table)
Inland Flooding114135211901996 to 2026-06-30
Landslide310001301996 to 2026-06-30
Lightning2000001996 to 2026-06-30
Strong Wind18620535101955 to 2026-06-30Includes 61 High Wind and 121 Strong Wind records.
Tornado1000101950 to 2026-06-30
Tsunami0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Volcanic Activity0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Wildfire23101001996 to 2026-06-30
Winter Weather2000901996 to 2026-06-30

Notable Storm Events records

Sources: 1, 6, 7

DateEvent typeMagnitude or extentDamagenominal dollarsDeaths, injuriesdirect onlyLocationFlagsWhy listed
2026-03-21Strong Wind26 kt (30 mph) estimated gust$0 property; $0 crops, reported for the zone (2026 dollars)1, 1NWS zone CAZ505 (COASTAL NORTH BAY INCLUDING POINT REYES NATIONAL SEASHORE), zone-levelnew since last plan; within last 5 yearsdeaths or injuries recorded
2025-12-25Thunderstorm Wind78 kt (90 mph) measured gust$0 property; $0 crops (2025 dollars)0, 0WOODACREnew since last plan; within last 5 yearsB1-c worst recorded: Thunderstorm Wind
2025-12-24High Wind94 kt (108 mph) measured gust$0 property; $0 crops, reported for the zone (2025 dollars)0, 0NWS zone CAZ502 (MARIN COASTAL RANGE), zone-levelnew since last plan; within last 5 yearsB1-c worst recorded: High Wind and Strong Wind
2024-10-02Heat$0 property; $0 crops, reported for the zone (2024 dollars)0, 19NWS zone CAZ506 (NORTH BAY INTERIOR VALLEYS), zone-levelnew since last plan; within last 5 yearsB1-c worst recorded: Excessive Heat, Heat
2020-08-17Wildfiredamage not reported3, 5NWS zone CAZ507 (NORTH BAY MOUNTAINS), zone-leveldeaths or injuries recorded
2013-05-01Wildfire$500,000 property; $0 crops, reported for the zone (2013 dollars)0, 0NWS zone CAZ507 (NORTH BAY MOUNTAINS), zone-levelB1-c worst recorded: Wildfire
2009-09-12Lightning$30,000 property; $0 crops (2009 dollars)0, 0MILL VLYB1-c worst recorded: Lightning
2006-04-01Debris Flow$14,400,000 property; $20,000,000 crops, reported for the zone (2006 dollars)1, 0NWS zone CAZ506 (NORTH BAY INTERIOR VALLEYS), zone-levelB1-c worst recorded: Debris Flow
2006-03-11Winter Weatherdamage not reported2, 15NWS zone CAZ505 (COASTAL NORTH BAY INCLUDING POINT REYES NATIONAL SEASHORE), zone-leveldeaths or injuries recorded
2006-01-01Flood$108,000,000 property; crops not reported (2006 dollars)0, 0COUNTYWIDEB1-c worst recorded: Flash Flood, Flood, Lakeshore Flood
2005-12-31Coastal Flood$340,000 property; crops not reported, reported for the zone (2005 dollars)0, 0NWS zone CAZ505 (COASTAL NORTH BAY INCLUDING POINT REYES NATIONAL SEASHORE), zone-levelB1-c worst recorded: Coastal Flood, Storm Surge/Tide
1996-12-23TornadoF1, 6 mi within this county, 20 yd wide$200,000 property; $5,000 crops (1996 dollars)0, 0TOMALESB1-c worst recorded: Tornado

The full list is in the Excel file, sheet "B1-d Storm Events history" (432 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 Flooding1.62events per year at a location (modeled)about 1.6 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 Wave0event-days per yearnone modeledPossible (from Storm Events: 2 of 30 years)event-days in 2 of 30 years, 1996 to 2025 (6.67%)02005-11-12 to 2024-11-12 (19 years)countywideNRI models no cold wave event-days here (2005-11-12 to 2024-11-12, 19 years); Storm Events has a record in 2 of 30 years. The descriptor comes from Storm Events, which records events NRI's definition leaves out.
Drought29event-days per yearabout 29 days per yearevent-days in 0 of 30 years, 1996 to 2025 (0%)9592000 to 2025 (25.25 years; D3 and D4 only)countywideNo Storm Events drought record, 1996 to 2025
Earthquake0.0975annual probability at a locationchance a given location in the county has at least minor-damage shaking in a year: 9.75%not shownmodeledsee B1-fNo descriptor (Storm Events does not record earthquakes).
Hail0.0199events per yearabout 1 in 50 yearsPossibleFEMA annualized frequency (modeled)0.8 (modeled)1986 to 2023 (38 years)countywide
Heat Wave4.53event-days per yearabout 4.53 days per yearLikely (from Storm Events: 8 of 30 years)event-days in 8 of 30 years, 1996 to 2025 (26.7%)43.42005-11-12 to 2024-11-12 (19 years)countywide
Hurricaneevents per year1851 to 2024 (Atlantic); 1949 to 2024 (Pacific)see B1-fNot Applicable in NRI for this county; no descriptor.
Ice Stormevent-days per year1946-12-31 to 2014-02-12 (67 years)countywideNot Applicable in NRI for this county; no descriptor.
Inland Flooding2.11event-days per yearabout 2.11 days per yearLikely (from Storm Events: 19 of 30 years)event-days in 19 of 30 years, 1996 to 2025 (63.3%)591996 to 2023 (28 years)see B1-f
Landslide12events per year (modeled)about 12 per yearHighly likelyFEMA annualized frequency (modeled)not shownmodeledsee B1-f
Lightning3.29days per year with a strikeabout 3.29 days per yearHighly likelyFEMA annualized frequency (modeled)not shown1995 to 2023 (29 years; CONUS)countywide
Strong Wind0.0315events per yearabout 1 in 32 yearsPossibleFEMA annualized frequency (modeled)11986 to 2023 (38 years)countywide
Tornado0.0498events per yearabout 1 in 20 yearsPossibleFEMA annualized frequency (modeled)not shown1950 to 2023 (EF2+); 1986 to 2023 (EF0-1)see B1-f
Tsunami0.342annual probability at the most exposed location (used in place of a county value)chance at the county's most exposed location in a year: 34.2%Storm Events records in 0 of 30 years, 1996 to 2025 (0%)not shownmodeledsee B1-fNo descriptor: no Storm Events record 1996 to 2025
Volcanic Activity0.0001annual probabilityabout 1 in 10,000 yearsUnlikelyFEMA annualized frequency (modeled)not shownmodeledsee B1-f
Wildfire0.00256annual probability at a locationchance a given location in the county burns in a year: 0.256%Likely (from Storm Events: 7 of 30 years)Storm Events records in 7 of 30 years, 1996 to 2025 (23.3%)not shownmodeledsee B1-fDescriptor from Storm Events, not NRI.
Winter Weather0.392event-days per yearabout 0.392 days per yearPossible (from Storm Events: 2 of 30 years)event-days in 2 of 30 years, 1996 to 2025 (6.67%)4.822005-11-12 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 20250300
Hail2.00 in+1996 to 20250300
Thunderstorm Wind (counted as NRI Strong Wind)50-64 kt1996 to 20253300.1
Thunderstorm Wind (counted as NRI Strong Wind)65 kt+1996 to 20251300.0333
Thunderstorm Wind (counted as NRI Strong Wind)unmeasured or below 50 kt1996 to 20250300
TornadoEF0-11996 to 20251300.0333
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 Flooding39 of 6270.995.3100.0Very High 9, Relatively High 10, Relatively Moderate 10, Relatively Low 7, Very Low 3, No Rating 23
Cold Wave0 of 62No Rating 62
Drought16 of 6269.579.094.7Relatively Moderate 3, Relatively Low 5, Very Low 8, No Rating 46
Earthquake62 of 6280.092.999.6Very High 10, Relatively High 40, Relatively Moderate 12
Hail62 of 621.12.414.0Very Low 62
Heat Wave62 of 622.924.551.3Relatively Low 43, Very Low 19
Hurricane0 of 62Not Applicable 62
Ice Storm0 of 62Not Applicable 62
Inland Flooding62 of 624.084.299.7Very High 16, Relatively High 19, Relatively Moderate 17, Relatively Low 8, Very Low 2
Landslide61 of 6220.996.299.9Very High 1, Relatively High 4, Relatively Moderate 29, Relatively Low 20, Very Low 7, No Rating 1
Lightning62 of 621.512.424.2Relatively Low 7, Very Low 55
Strong Wind62 of 623.510.516.2Very Low 62
Tornado62 of 622.27.118.4Very Low 62
Tsunami38 of 6212.964.993.0Relatively Moderate 8, Relatively Low 19, Very Low 11, Not Applicable 24
Volcanic Activity58 of 6240.755.973.4Very Low 58, No Rating 4
Wildfire56 of 6219.581.999.3Very High 1, Relatively High 3, Relatively Moderate 14, Relatively Low 25, Very Low 13, No Rating 6
Winter Weather57 of 6210.814.719.1Relatively Low 1, Very Low 56, No Rating 5

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 drought, hail, heat wave, 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
Marin CountyCountyApproved, expires 2029-01-30FMA RL 3, SRL 11; any 83$31,488,275.470 total; 0 since its planIncludes $27,573,213.69 for declarations not counted as hazard incidents (DR-4482-CA).
Belvedere cityCityApproved, expires 2029-01-30FMA RL 0, SRL 0; any 2no Public Assistance recorded0 total; 0 since its plan
Corte Madera townTownApproved, expires 2029-01-30FMA RL 0, SRL 1; any 11$236,377.275 total; 0 since its plan
Fairfax townTownApproved, expires 2029-01-30FMA RL 1, SRL 1; any 6$2,016,200.401 total; 0 since its planIncludes $158,015.60 for declarations not counted as hazard incidents (DR-4482-CA).
Larkspur cityCityApproved, expires 2029-01-30FMA RL 0, SRL 1; any 7$1,796,426.848 total; 2 since its plan
Mill Valley cityCityApproved, expires 2029-01-30FMA RL 0, SRL 1; any 9$1,522,358.580 total; 0 since its plan
Novato cityCityApproved, expires 2029-01-30FMA RL 0, SRL 2; any 41$284,449.643 total; 0 since its plan
Ross townTownApproved, expires 2029-01-30FMA RL 0, SRL 4; any 15$211,944.832 total; 0 since its plan
San Anselmo townTownApproved, expires 2029-01-30FMA RL 0, SRL 0; any 4$2,946,674.562 total; 0 since its planIncludes $18,574.12 for declarations not counted as hazard incidents (DR-4482-CA).
San Rafael cityCityApproved, expires 2029-01-30FMA RL 0, SRL 7; any 46$2,889,381.914 total; 0 since its planIncludes $119,580.96 for declarations not counted as hazard incidents (DR-4482-CA).
Sausalito cityCityApproved, expires 2029-01-30FMA RL 0, SRL 2; any 6$728,566.3410 total; 0 since its plan
Tiburon townTownApproved, expires 2029-01-30FMA RL 0, SRL 0; any 4$549,751.670 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).

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.

  • 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 2024-01-31county-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$19,199,217,113n/a70,387$19,709,910n/a$73,3780.103%$0
Cold Wave$0$00$0$0$0building exposure is 0 in NRI
Droughtn/a$11,007,168n/an/a$183,012n/a1.66% (agriculture)NRI has no building exposure for this hazard; agriculture shown
Earthquake$115,752,540,914n/a262,321$83,866,586n/a$25,801,3130.0725%
Hail$70,463,360,157$122,756,581262,172$6,571$531$1,556under 0.0001%
Heat Wave$70,463,360,157$122,756,581262,168$69$327$1,300,244under 0.0001%$0
HurricaneNot Applicable in NRI for this county
Ice StormNot Applicable in NRI for this county
Inland Flooding$70,166,969,817$83,284,89240,992$115,135,489$315,166$561,435n/a (see note)$20NRI 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$18,483,525,867n/a67,047$783,700n/a$1,130,2500.00424%
Lightning$70,463,360,157n/a262,172$7,957n/a$138,348under 0.0001%
Strong Wind$70,463,360,157$122,756,581262,172$45,791$8$50,207under 0.0001%$0$50Storm Events damage since the plan includes 5 zone-level Strong Wind records ($50): a NOAA non-thunderstorm wind type, outside NRI's Strong Wind definition.
Tornado$70,463,360,157$122,756,581262,172$180,823$86$61,5540.000257%
Tsunami$36,914,806,250n/a39,734$6,374,117n/a$00.0173%
Volcanic Activity$70,463,360,157n/a262,172under $1n/a$56under 0.0001%
Wildfire$7,976,111,226$88,046,52335,856$3,460,593$1,063$154,6970.0434%$10
Winter Weather$61,479,644,470$91,765,291232,066$56under $1$3,060under 0.0001%

Totals since 2024-01-31 (Storm Events through 2026-06-30): 15 county-coded records, 15 with a damage value recorded (including $0), $20; 30 zone-level records, 30 with a damage value recorded (including $0), $60 reported for the zone; Public Assistance: no counted declaration since the plan.

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
Population262,172
Building value (total, not at risk)$70,463,360,157
Agriculture value (total, not at risk)$122,756,581
NRI risk rating (all hazards)Relatively High
Expected annual loss, buildings and agriculture, all hazards$230,071,854
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)$29,276,098
Social vulnerability ratingRelatively 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)4Severe repetitive loss, FMA definition (44 CFR 77.2)30
Repetitive loss, NFIP insurance definition233Severe repetitive loss, NFIP insurance definition28

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

Repeat-flood properties: county and state-level rows

Sources: 1, 4

ScopeRL, FMApropertiesSRL, FMApropertiesRL, NFIPpropertiesSRL, NFIPpropertiesAny categorypropertiesMitigatedpropertiesCurrently insuredproperties
County total43023328235181
of which: Marin County (unincorporated area)311831183022
of which: Fairfax town1161604
of which: Mill Valley city0191902
of which: Novato city0241241022
of which: Ross town041531509
of which: San Anselmo town0040404
of which: Sausalito city0262601
of which: Belvedere city0020200
of which: Tiburon town0040401
of which: Corte Madera town011111102
of which: Larkspur city0171702
of which: San Rafael city0744646112
of which: Unknown (community ID Unknown in FEMA data)0010100
Statewide, no county in FEMA's file0130410

The statewide row counts properties FEMA's file gives with no county in this state; they are listed for reference and are not in this county's counts.

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

Sources: 1, 4

JurisdictionNFIP community IDRL, FMApropertiesSRL, FMApropertiesRL, NFIPpropertiesSRL, NFIPpropertiesAny categorypropertiesMitigatedpropertiesCurrently insuredproperties
Marin County060173311831183022
Belvedere city0604290020200
Corte Madera town065023011111102
Fairfax town0601751161604
Larkspur city0650400171702
Mill Valley city0601770191902
Novato city0601780241241022
Ross town060179041531509
San Anselmo town0601800040404
San Rafael city0650580744646112
Sausalito city0601820262601
Tiburon town0604300040401

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 residential32117119173170
2 to 4 unit residential011111102
other residential0161601
non-residential174574508
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 229 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, organized by the items of FEMA's Local Mitigation Plan Review Tool, Element B. Each section heading names the item its tables support; the plan and FEMA's review decide whether the 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). Marin County, CA: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-30; County FIPS 06041). Automated baseline. https://hazardplain.org/ca/06041/ 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

Hazard Plain release 2026-10. As of 2026-09-30; Storm Events data through 2026-06-30. Automated baseline.