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Natural hazard risk in Marin County, California

Updated October 30, 2026. Based on FEMA, NOAA and OpenFEMA data. Published by Humblebee.

FEMA overall Risk Index rating: Relatively High (score 96.3 of 100)[5]

Expected annual loss (FEMA)
$259.3 million[1]
Federal disaster declarations since 1964
24[2]
NFIP flood claims paid, 1978 to 2026
$54.9 million[3]
Tornadoes recorded, 1950 to 2024
1[4]

FEMA's National Risk Index rates overall natural hazard risk in Marin County Relatively High compared with other US counties, with a Risk Index score of 96.3 out of 100[5]. Within the county, the hazards with the highest FEMA scores are landslide, earthquake and coastal flooding[6].

FEMA risk ratings for each hazard

Ratings and expected losses from the FEMA National Risk Index. Each rating compares this county with all US counties for that hazard, from Very Low to Very High. They are planning estimates, not predictions, and they do not describe any single property.

FEMA's National Risk Index estimates Expected Annual Loss from all 18 natural hazards in Marin County at $259.3 million a year, rated Relatively High[1]. This is FEMA's estimate of average yearly economic loss, not money anyone paid, and it does not predict next year's losses[7]. Inland flooding accounts for $116.0 million a year[8] and earthquake for $109.7 million a year[9], with coastal flooding at $19.8 million a year[10]. FEMA rates Social Vulnerability in Marin County Relatively Low (score 24.7), a measure of how susceptible social groups are to the harm hazards cause[11]. FEMA rates Community Resilience Very High (score 99.1), which describes the ability to prepare for, withstand and recover from hazards[12].

Hazards sorted by FEMA hazard-type Risk Index score, highest first
HazardFEMA risk ratingExpected annual loss
LandslideRelatively High$1.9 million[13]
EarthquakeRelatively High$109.7 million[9]
Coastal FloodingVery High$19.8 million[10]
Inland FloodingRelatively High$116.0 million[8]
WildfireRelatively Moderate$3.6 million[14]
Heat WaveRelatively Low$1.3 million[15]
TsunamiRelatively Moderate$6.4 million[16]
Volcanic ActivityVery Low$56[17]
DroughtRelatively Low$183,000[18]
LightningRelatively Low$146,000[19]
TornadoVery Low$242,000[20]
Strong WindVery Low$96,000[21]
Winter WeatherVery Low$3,116[22]
HailVery Low$8,658[23]

Rated Not Applicable by FEMA for this county: avalanche, hurricane, ice storm[24].

Social vulnerability and community resilience

FEMA uses these two ratings to scale expected losses into the Risk Index.

FEMA measureRatingScore
Social vulnerabilityRelatively Low24.7[11]
Community resilienceVery High99.1[12]

Flooding and flood insurance

FEMA rates coastal flooding risk in Marin County Very High[10] and inland flooding risk Relatively High[8] compared with other US counties. OpenFEMA lists 4,542 residential flood insurance contracts in force as of 2026-08-03, out of 84,609 residential structures, a penetration rate of 5.4%[25]. From 1978 to 2026, 3,301 NFIP claims were filed for losses in the county, and NFIP paid $54.9 million in total[3]. The years with the most paid claims were 2005 (515), 1982 (509) and 1983 (382)[3].

Measure Value
Coastal Flooding, FEMA risk rating[10] Very High, $19.8 million expected loss a year
Inland Flooding, FEMA risk rating[8] Relatively High, $116.0 million expected loss a year
NFIP residential flood policies in force (2026)[25] 4,542 of 84,609 homes
Homes in FEMA's mapped high-risk flood area (SFHA)[25] 9,823, of which 3,734 insured
NFIP flood claims, 1978 to 2026[3] 3,301 filed, $54.9 million paid

Is a specific address in a flood zone? Only FEMA's flood maps answer that, property by property[26]. This page describes the whole county.

Search an address on the FEMA Flood Map Service Center

Disaster declarations and tornado records

OpenFEMA lists 24 federal disaster declarations for natural hazards that include Marin County since 1964, with severe storm (10) and flood (9) the most common incident types[2]. The most recent was DR-4699-CA, Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, And Mudslides, declared 2023-04-03[27]. NOAA's Storm Prediction Center tornado database (1950 to 2024) records 1 tornado in Marin County, rated F1, on 1996-12-23[4].

Federal disaster declarations for natural hazards that include Marin County, since 1964
Incident type Declarations
Severe Storm[2] 10
Flood[2] 9
Coastal Storm[2] 1
Earthquake[2] 1
Freezing[2] 1
Drought[2] 1
Hurricane[2] 1
Most recent declarations
Declaration Incident Declared
DR-4699-CA[27] Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, And Mudslides 2023-04-03
DR-4683-CA[27] Severe Winter Storms, Flooding, Landslides, And Mudslides 2023-01-14
EM-3591-CA[27] Severe Winter Storms, Flooding, And Mudslides 2023-01-09
DR-4434-CA[27] Severe Winter Storms, Flooding, Landslides, And Mudslides 2019-05-17
DR-4431-CA[27] Severe Winter Storms, Flooding, Landslides, And Mudslides 2019-05-01

How to prepare

Steps from Ready.gov, FEMA's preparedness site, for the hazards with the highest FEMA ratings here. Follow instructions from local officials and the National Weather Service when a warning is issued.

Earthquakes

Before

  • Practice Drop, Cover, and Hold On with your family and coworkers.
  • Sign up for earthquake alerts that can warn you before shaking starts.
  • Make a plan with an out-of-state contact and a place to meet if you get separated.
  • Anchor heavy items such as bookcases, refrigerators and water heaters, and keep heavy things on low shelves.
  • Consider earthquake insurance. Standard homeowners policies do not cover earthquake damage.

During

  • Drop to your hands and knees, cover your head and neck, and hold on until the shaking stops.
  • Indoors, stay where you are and avoid doorways. Outdoors, move to an open area away from buildings and power lines.
  • If you are driving, pull over, stop and set the parking brake.

Source: Ready.gov, earthquakes

Floods

Before

  • Check your flood risk with FEMA's Flood Map Service Center, and remember that floods do not follow map lines.
  • Sign up for your community's warning system. NOAA Weather Radio also broadcasts alerts.
  • Buy flood insurance through the NFIP well before a disaster. Homeowners policies do not cover flooding, and a new policy typically takes up to 30 days to go into effect.
  • Make a household plan with evacuation routes, shelter locations and what to do in a flash flood.
  • Keep important documents in a waterproof container and make password-protected digital copies.

During

  • If you are told to evacuate, leave right away and never drive around barricades.
  • Do not walk, swim or drive through floodwater. Six inches of moving water can knock you down.
  • If you are trapped in a building, go to the highest level, but do not climb into a closed attic.

Source: Ready.gov, floods

Wildfires

Before

  • Sign up for community alerts and watch for air quality alerts.
  • Make sure everyone knows the evacuation plan, including for school, work and other places you go often.
  • Keep a fire-resistant zone of at least 30 feet around your home, clear of leaves and debris.
  • Use fire-resistant building materials and keep a hose long enough to reach every part of your property.
  • Pick a room you can seal off from outside air and keep a portable air cleaner ready.

During

  • Leave right away when authorities tell you to evacuate.
  • If you are trapped, call 9-1-1 with your location and turn on lights to help rescuers find you.
  • If you are not ordered to leave but there is smoke, stay in a safe indoor place or go to a community building with less smoke.

Source: Ready.gov, wildfires

Questions people ask

Is Marin County at risk of flooding?
FEMA rates coastal flooding risk Very High[10] and inland flooding risk Relatively High[8] compared with other US counties. NFIP paid $54.9 million for flood claims in the county from 1978 to 2026[3].
How do I check if an address in Marin County is in a flood zone?
County ratings do not tell you the flood zone of a single address. Look up the address on FEMA's Flood Map Service Center or ask the local floodplain manager[26].
What is the earthquake risk in Marin County?
FEMA rates earthquake risk Relatively High compared with other US counties, with a score of 98.7 and Expected Annual Loss of $109.7 million a year[9].
Is Marin County at risk of wildfire?
FEMA rates wildfire risk in Marin County Relatively Moderate compared with other US counties, with a score of 94.5 and Expected Annual Loss of $3.6 million a year[14].
How many federal disasters have been declared in Marin County?
OpenFEMA lists 24 federal disaster declarations for natural hazards that include Marin County since 1964, 21 of them major disasters[2].

Facts and sources

  1. FEMA National Risk Index (version 1.20, December 2025): Expected Annual Loss from all 18 natural hazards in Marin County is $259.3 million a year (Expected Annual Loss rating Relatively High, score 96.8). Of this, buildings account for $229.6 million, injuries and deaths (converted to dollars by FEMA) for $29.3... FEMA National Risk Index
  2. OpenFEMA Disaster Declarations Summaries list 24 federal disaster declarations for natural hazards that include Marin County since 1964 (21 major disaster, 3 emergency or fire management). By incident type: severe storm 10, flood 9, coastal storm 1, earthquake 1, freezing 1, drought 1, hurricane 1. Biological (such... OpenFEMA Disaster Declarations
  3. HazardFacts tally of OpenFEMA NFIP Redacted Claims (losses from 1978 to 2026): 3,301 National Flood Insurance Program claims were filed for losses in Marin County, 2,423 of them with a payment, and NFIP paid $54.9 million in total (building, contents and increased cost of compliance, in dollars of the year paid).... OpenFEMA NFIP claims
  4. NOAA Storm Prediction Center tornado database (1950 to 2024): 1 recorded tornadoes touched Marin County. The strongest were rated F1 (most recent of them on 1996-12-23). 0 were rated F3/EF3 or stronger. The most recent recorded tornado was on 1996-12-23. Ratings used the Fujita scale until early 2007 and the... NOAA Storm Prediction Center
  5. FEMA National Risk Index (version 1.20, December 2025): the overall natural hazard Risk Index rating for Marin County is Relatively High, with a Risk Index score of 96.3 out of 100. The score is the county's percentile rank among all US counties. FEMA National Risk Index
  6. Among the 18 hazards in the FEMA National Risk Index (version 1.20, December 2025), the hazards with the highest hazard-type Risk Index scores for Marin County are landslide (99.2, Relatively High), earthquake (98.7, Relatively High), coastal flooding (97.2, Very High). HazardFacts sorted FEMA's published scores;... FEMA National Risk Index
  7. FEMA's National Risk Index FAQ (December 2025): Expected Annual Loss is FEMA's estimate of the average economic loss in dollars from natural hazards each year. The index is not meant to predict how much damage a community will have in the next year, and a hazard can still cause damage where a rating is low. Scores... FEMA National Risk Index documentation
  8. FEMA National Risk Index (version 1.20, December 2025), inland flooding in Marin County: Risk Index rating Relatively High (score 96.5 of 100). Expected Annual Loss $116.0 million a year (rating Relatively High). Annualized frequency 2.11 event-days per year, from recorded occurrences over a period of record of 26... FEMA National Risk Index
  9. FEMA National Risk Index (version 1.20, December 2025), earthquake in Marin County: Risk Index rating Relatively High (score 98.7 of 100). Expected Annual Loss $109.7 million a year (rating Relatively High). FEMA's modeled annual frequency is 0.0975 events per year. FEMA National Risk Index
  10. FEMA National Risk Index (version 1.20, December 2025), coastal flooding in Marin County: Risk Index rating Very High (score 97.2 of 100). Expected Annual Loss $19.8 million a year (rating Very High). FEMA's modeled annual frequency is 1.6249 events per year. FEMA National Risk Index
  11. FEMA National Risk Index (version 1.20, December 2025): Social Vulnerability rating for Marin County is Relatively Low (score 24.7). FEMA describes social vulnerability as how susceptible social groups are to the harm natural hazards cause. FEMA National Risk Index
  12. FEMA National Risk Index (version 1.20, December 2025): Community Resilience rating for Marin County is Very High (score 99.1). FEMA describes community resilience as a community's ability to prepare for, withstand and recover from hazards. FEMA National Risk Index
  13. FEMA National Risk Index (version 1.20, December 2025), landslide in Marin County: Risk Index rating Relatively High (score 99.2 of 100). Expected Annual Loss $1.9 million a year (rating Relatively High). FEMA National Risk Index
  14. FEMA National Risk Index (version 1.20, December 2025), wildfire in Marin County: Risk Index rating Relatively Moderate (score 94.5 of 100). Expected Annual Loss $3.6 million a year (rating Relatively Moderate). FEMA's modeled annual frequency is 0.0026 events per year. FEMA National Risk Index
  15. FEMA National Risk Index (version 1.20, December 2025), heat wave in Marin County: Risk Index rating Relatively Low (score 74.6 of 100). Expected Annual Loss $1.3 million a year (rating Relatively Low). Annualized frequency 4.53 event-days per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  16. FEMA National Risk Index (version 1.20, December 2025), tsunami in Marin County: Risk Index rating Relatively Moderate (score 69.2 of 100). Expected Annual Loss $6.4 million a year (rating Relatively Moderate). FEMA National Risk Index
  17. FEMA National Risk Index (version 1.20, December 2025), volcanic activity in Marin County: Risk Index rating Very Low (score 63.5 of 100). Expected Annual Loss $56 a year (rating Very Low). FEMA National Risk Index
  18. FEMA National Risk Index (version 1.20, December 2025), drought in Marin County: Risk Index rating Relatively Low (score 51.6 of 100). Expected Annual Loss $183,000 a year (rating Relatively Low). Annualized frequency 28.97 event-days per year, from recorded occurrences over a period of record of 22 years. FEMA National Risk Index
  19. FEMA National Risk Index (version 1.20, December 2025), lightning in Marin County: Risk Index rating Relatively Low (score 34.1 of 100). Expected Annual Loss $146,000 a year (rating Relatively Low). Annualized frequency 3.29 events per year, from recorded occurrences over a period of record of 24 years. FEMA National Risk Index
  20. FEMA National Risk Index (version 1.20, December 2025), tornado in Marin County: Risk Index rating Very Low (score 18.5 of 100). Expected Annual Loss $242,000 a year (rating Very Low). Annualized frequency 0.05 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  21. FEMA National Risk Index (version 1.20, December 2025), strong wind in Marin County: Risk Index rating Very Low (score 11.1 of 100). Expected Annual Loss $96,000 a year (rating Very Low). Annualized frequency 0.03 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  22. FEMA National Risk Index (version 1.20, December 2025), winter weather in Marin County: Risk Index rating Very Low (score 4.0 of 100). Expected Annual Loss $3,116 a year (rating Very Low). Annualized frequency 0.39 events per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  23. FEMA National Risk Index (version 1.20, December 2025), hail in Marin County: Risk Index rating Very Low (score 3.6 of 100). Expected Annual Loss $8,658 a year (rating Very Low). Annualized frequency 0.02 events per year, from recorded occurrences over a period of record of 37 years. FEMA National Risk Index
  24. FEMA National Risk Index (version 1.20, December 2025) rates these hazards Not Applicable for Marin County: avalanche, hurricane, ice storm. FEMA uses Not Applicable when its source data has no historical record of the hazard in the community and the hazard is not considered geographically possible there. FEMA National Risk Index documentation
  25. NFIP Residential Penetration Rates (OpenFEMA, as of 2026-08-03): 4,542 residential flood insurance contracts were in force in Marin County, out of 84,609 residential structures, a penetration rate of 5.4%. Inside FEMA's mapped Special Flood Hazard Area there were 9,823 residential structures and 3,734 contracts, a... OpenFEMA NFIP penetration rates
  26. FEMA's Flood Map Service Center is the official public source for flood maps (Flood Insurance Rate Maps) produced under the National Flood Insurance Program. Flood zones apply to specific properties: look up an address there or ask the local floodplain manager. County-level ratings do not tell you the flood zone of... FEMA Flood Map Service Center
  27. Most recent federal disaster declarations for natural hazards (table on this page). OpenFEMA Disaster Declarations

FEMA's National Risk Index compares each county with all other US counties. Ratings are relative (Very Low to Very High), not a measure of safety. Never call a place safe, unsafe, good or bad to live in. Risk Index and Expected Annual Loss values are FEMA estimates for planning. They do not predict next year's losses and do not apply to a single property. Flood zones are set by FEMA flood maps for specific properties. County ratings and flood insurance counts do not tell anyone whether an address is in a flood zone. Disaster declaration, NFIP and tornado counts are records of the past for this county only. Do not compare with other counties unless a fact does.

Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties, v1.20 (December 2025). Retrieved from fema.maps.arcgis.com on October 30, 2026. This product uses the Federal Emergency Management Agency's National Risk Index dataset API or downloadable datasets 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). This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.