Photo: Cullen328 · CC BY-SA 3.0FEMA puts Sonoma’s expected hazard damage per building above that of 95% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Sonoma gets a D− for hazard risk: higher expected damage per building than 95% of U.S. towns, #575 of 847 in California. Most of that expected damage is river and rain flooding (68%), then earthquakes (32%). Flood insurance has paid 42 claims here since 1978.
Graded on FEMA’s expected yearly building damage per dollar of building value (NRI v1.20, December 2025), weighted by where residents live; flood claims are shown, not graded. How hazard risk is graded
What stands out about Sonoma’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Sonoma 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
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.
What’s behind Sonoma’s grade
River and rain flooding is 68% of the building damage FEMA expects in Sonoma, and Sonoma’s rate of river and rain flooding damage is in the top 4% of U.S. census tracts. Earthquakes add 32%, at a rate in the top 8% of U.S. census tracts.
D− #575 of 847 in California; higher expected damage per building than 95% of U.S. towns (21,298).
Sonoma’s residents live in 4 census tracts; FEMA’s figures are combined by where they live.
The typical California town has higher expected damage than 92% of U.S. towns; within the state, Sonoma has more expected damage per building than 68% of California towns.
In dollars, FEMA expects about $12.8M a year in losses across Sonoma: $11.6M to buildings, the rest to people and crops.
Does Sonoma flood? Sometimes: 42 flood claims since 1978
Every paid claim on a federal flood insurance policy in Sonoma, from FEMA’s records: 7.0 per 1,000 homes, more than 67% of the 13,809 U.S. towns with a flood insurance record.
- The Pineapple Express - Southern2 claims · $28K
Sonoma isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Sonoma County.4 federal disasters brought FEMA money to Sonoma
Disasters that paid out in Sonoma itself (aid to households or repair grants to the City of Sonoma), newest first, with that year’s flood claims.
- 2020Wildfires133 households applied for aid$6K aid approved
- 2020Wildfires457 households applied for aid$72K aid approved
- 2017Wildfires1,681 households applied for aid$132K aid approved$64K to the City of Sonoma for repairs
- 2005Severe Storms, Flooding, Mudslides, and Landslides155 households applied for aid$228K aid approved$18K to the City of Sonoma for repairs1 flood claim paid that year
Sonoma County has had 24 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.
Also 8 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in Sonoma County, 2004–2020.
Old photos of Sonoma after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Sonoma archive →Sonoma and its neighbors
Sonoma has the lowest expected damage per building of the 2 graded towns here. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Sonoma | D−more damage than 95% | river and rain flooding | 42 |
| El Verano | 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 Sonoma 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.
- 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 Sonoma
Is Sonoma at risk for natural disasters?
On FEMA’s National Risk Index, Sonoma has higher expected damage per building than 95% of U.S. towns: D− for hazard risk, #575 of 847 in California. Most of the expected damage is river and rain flooding (68%) and earthquakes (32%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Sonoma flood?
Flood insurance has paid 42 claims in Sonoma since 1978, $713K in all, or 7.0 per 1,000 homes, more than 67% of U.S. towns with a flood insurance record. 2 properties have flooded more than once. The most claims came from Pineapple Express - Southern (2).
Is Sonoma 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 Sonoma County, 31% of homes in mapped flood zones carry federal flood insurance, and 1.1% of all homes do.
How much is flood insurance in Sonoma?
FEMA’s Community Rating System list shows no discount for Sonoma’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 Sonoma?
By FEMA money that reached Sonoma, Severe Storms, Flooding, Mudslides, and Landslides (2005): 155 households applied for aid, $228K approved, and $18K to the City of Sonoma for repairs. By flood claims, Pineapple Express - Southern: 2 paid, $28K.
Is Sonoma at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (68%), and Sonoma’s rate for it is in the top 4% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Sonoma.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Sonoma’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.