Storms, floods and disasters in San Geronimo
San Geronimo isn’t graded for hazard risk: San Geronimo has 583 residents; we grade towns of 1,000 or more. Flood insurance has paid 34 claims here since 1982.
What San Geronimo faces
Each hazard’s share of the building damage FEMA expects here, and how its rate compares with the rest of the country.
River and rain flooding
Earthquakes
Wildfire
Shares are of FEMA’s expected building damage, the measure the grade uses; ranks compare each hazard’s building-damage rate with all 85,154 U.S. census tracts. In FEMA’s terms, river and rain flooding is FEMA’s “Inland Flooding” (rivers and streams overflowing their banks, or rain overwhelming drainage). FEMA defines coastal flooding as high or rising tides and storm surge, so surge damage is counted there. Drought isn’t listed: FEMA counts its losses in crops only.
Does San Geronimo flood? Sometimes: 34 flood claims since 1982
Every paid claim on a federal flood insurance policy in San Geronimo, from FEMA’s records.
San Geronimo isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Marin County.1 federal disaster brought FEMA money to San Geronimo
Disasters that paid out in San Geronimo itself (aid to households or repair grants to San Geronimo), newest first, with that year’s flood claims.
- 2005Severe Storms, Flooding, Mudslides, and Landslides2 households applied for aid$5K aid approved17 flood claims paid that year
Marin County has had 22 natural disasters declared by the President since 1953, most often severe storms, then floods. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of San Geronimo after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the San Geronimo archive →San Geronimo and its neighbors
How expected damage per building compares across the town line. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Woodacre | D−among the highest damage | river and rain flooding | — |
| Lagunitas-Forest Knolls | D−among the highest damage | river and rain flooding | — |
Hazard risk = FEMA’s expected yearly building damage per dollar of building value, vs. the 21,298 U.S. towns we grade; the map is shaded by fifths of the same scale. Flood claims = paid federal flood insurance claims on record.
Get ready for what San Geronimo faces
A short kit for the hazards that drive the building damage here, what to check before you buy, and where neighbors get alerts.
- Turn around at flooded roads: a foot of moving water can carry off a car.
- Flood insurance usually takes 30 days to start, so buy it before the forecast.
- Keep papers and medicines up high, in a grab-and-go bag.
- Drop, cover and hold on.
- Strap tall furniture and the water heater to the wall.
- Know how to shut off the gas.
- Clear dead leaves and brush within 5 feet of the house.
- Sign up for local alerts and know two ways out.
- Keep N95 masks for smoky days.
- Look up the address on FEMA’s flood map.
- Ask the seller or landlord whether it has ever flooded, and what flood insurance costs there.
- Get a flood insurance quote early: policies usually start 30 days after you buy.
Know where neighbors sign up for alerts? Add it to the Handbook so everyone has it.
Questions about natural hazards in San Geronimo
Does San Geronimo flood?
Flood insurance has paid 34 claims in San Geronimo since 1982, $683K in all.
Is San Geronimo in a flood zone?
Flood zones are drawn street by street, so the answer depends on the address: look it up on FEMA’s flood map. In Marin County, 38% of homes in mapped flood zones carry federal flood insurance, and 5.4% of all homes do.
How much is flood insurance in San Geronimo?
FEMA’s Community Rating System list shows no discount for San Geronimo’s flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
What was the biggest storm in San Geronimo?
By FEMA money that reached San Geronimo, Severe Storms, Flooding, Mudslides, and Landslides (2005): 2 households applied for aid, $5K approved.
Storm stories
Memories, warnings and help from neighbors in San Geronimo.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where San Geronimo’s residents lived in the 2020 census; OpenFEMA: NFIP redacted claims, multiple-loss properties, community status book and residential penetration rates, housing assistance (owners and renters), public assistance funded projects, hazard mitigation properties and disaster declarations. Homes: Census ACS 2020–24. Preparedness tips: Ready.gov. FEMA’s model is an average of expected damage, not a forecast. How hazard risk is graded.