Photo: Karl98007 · CC BY-SA 3.0On FEMA’s figures, Sonora faces more hazard damage per building than 77% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Sonora gets a C− for hazard risk: higher expected damage per building than 77% of U.S. towns, #151 of 847 in California. Most of that expected damage is river and rain flooding (68%), then wildfire (29%). Flood insurance has paid 6 claims here since 1986.
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 Sonora 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
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.
What’s behind Sonora’s grade
River and rain flooding is 68% of the building damage FEMA expects in Sonora, and Sonora’s rate of river and rain flooding damage is higher than 77% of U.S. census tracts. Wildfire adds 29%, at a rate in the top 2% of U.S. census tracts.
C− #151 of 847 in California; higher expected damage per building than 77% of U.S. towns (21,298).
Sonora’s residents live in 3 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, Sonora has less expected damage per building than 82% of California towns.
In dollars, FEMA expects about $2.6M a year in losses across Sonora: $2.2M to buildings, the rest to people and crops.
Does Sonora flood? Rarely: 6 flood claims since 1986
Every paid claim on a federal flood insurance policy in Sonora, from FEMA’s records: 2.4 per 1,000 homes, fewer than 57% of the 13,809 U.S. towns with a flood insurance record.
- The California Atmospheric River2 claims · $38K
Sonora isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Tuolumne County.3 federal disasters brought FEMA money to Sonora
Disasters that paid out in Sonora itself (aid to households or repair grants to the City of Sonora), newest first, with that year’s flood claims.
- 2023Severe Winter Storms, Straight-line Winds, Flooding, Landslides, and Mudslides629 households applied for aid$2.1M aid approved$53K to the City of Sonora for repairs2 flood claims paid that year
- 2022Severe Winter Storms, Flooding, Landslides, and Mudslides$19K to the City of Sonora for repairs
- 2006Severe Storms, Flooding, Landslides, and Mudslides$50K to the City of Sonora for repairs
Tuolumne County has had 16 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 2 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in Tuolumne County, 2013–2026.
Old photos of Sonora after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Sonora archive →Sonora and its neighbors
Sonora has the lowest expected damage per building of the 3 graded towns here. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Sonora | C−more damage than 77% | river and rain flooding | 6 |
| East Sonora | C−more damage than 85% | wildfire | 1 |
| Jamestown | D−more damage than 98% | wildfire | — |
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 Sonora 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.
- 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 Sonora
Is Sonora at risk for natural disasters?
On FEMA’s National Risk Index, Sonora has higher expected damage per building than 77% of U.S. towns: C− for hazard risk, #151 of 847 in California. Most of the expected damage is river and rain flooding (68%) and wildfire (29%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Sonora flood?
Flood insurance has paid 6 claims in Sonora since 1986, $119K in all, or 2.4 per 1,000 homes, fewer than 57% of U.S. towns with a flood insurance record. The most claims came from California Atmospheric River (2).
Is Sonora 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 Tuolumne County, 24% of homes in mapped flood zones carry federal flood insurance, and 0.1% of all homes do.
How much is flood insurance in Sonora?
FEMA’s Community Rating System list shows no discount for Sonora’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 Sonora?
By FEMA money that reached Sonora, Severe Winter Storms, Straight-line Winds, Flooding, Landslides, and Mudslides (2023): 629 households applied for aid, $2.1M approved, and $53K to the City of Sonora for repairs. By flood claims, California Atmospheric River: 2 paid, $38K.
Is Sonora at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (68%), and Sonora’s rate for it is higher than 77% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Sonora.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Sonora’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.