Photo: Mliu92 · CC BY-SA 3.0More hazard damage per building is expected in San Bruno than in 94% of U.S. towns, mostly from earthquakes
On FEMA’s National Risk Index, San Bruno gets a D for hazard risk: higher expected damage per building than 94% of U.S. towns, #490 of 847 in California. Most of that expected damage is earthquakes (71%), then river and rain flooding (29%). Flood insurance has paid 22 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 San Bruno faces
Each hazard’s share of the building damage FEMA expects here, and how its rate compares with the rest of the country.
Earthquakes
River and rain flooding
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 San Bruno’s grade
Earthquakes are 71% of the building damage FEMA expects in San Bruno, and San Bruno’s rate of earthquakes damage is in the top 2% of U.S. census tracts. Next is river and rain flooding at 29% (higher than 65% of U.S. census tracts).
D #490 of 847 in California; higher expected damage per building than 94% of U.S. towns (21,298).
San Bruno’s residents live in 10 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, San Bruno has more expected damage per building than 58% of California towns.
In dollars, FEMA expects about $34.3M a year in losses across San Bruno: $23.4M to buildings, the rest to people and crops.
Does San Bruno flood? Sometimes: 22 flood claims since 1978
Every paid claim on a federal flood insurance policy in San Bruno, from FEMA’s records: 1.3 per 1,000 homes, fewer than 71% of the 13,809 U.S. towns with a flood insurance record.
- The California Atmospheric River4 claims · $42K
San Bruno isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: San Mateo County.4 federal disasters brought FEMA money to San Bruno
Disasters that paid out in San Bruno itself (aid to households or repair grants to the City of San Bruno), newest first, with that year’s flood claims.
- 2023Severe Winter Storms, Straight-line Winds, Flooding, Landslides, and Mudslides$40K to the City of San Bruno for repairs
- 2022Severe Winter Storms, Flooding, Landslides, and Mudslides48 households applied for aid$81K aid approved$238K to the City of San Bruno for repairs4 flood claims paid that year
- 2020Wildfires32 households applied for aid$28K aid approved
- 2017Severe Winter Storms, Flooding, and Mudslides$110K to the City of San Bruno for repairs1 flood claim paid that year
San Mateo County has had 19 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 San Mateo County, 2010–2020.
Old photos of San Bruno after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the San Bruno archive →San Bruno and its neighbors
San Bruno is 2nd of the 4 graded towns here, from least expected damage per building to most. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Pacifica | Dmore damage than 94% | earthquakes | 76 |
| San Bruno | Dmore damage than 94% | earthquakes | 22 |
| Millbrae | Dmore damage than 95% | earthquakes | 31 |
| South San Francisco | D−more damage than 96% | earthquakes | 76 |
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 Bruno faces
A short kit for the hazards that drive the building damage here, what to check before you buy, and where neighbors get alerts.
- Drop, cover and hold on.
- Strap tall furniture and the water heater to the wall.
- Know how to shut off the gas.
- 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.
- 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 Bruno
Is San Bruno at risk for natural disasters?
On FEMA’s National Risk Index, San Bruno has higher expected damage per building than 94% of U.S. towns: D for hazard risk, #490 of 847 in California. Most of the expected damage is earthquakes (71%) and river and rain flooding (29%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does San Bruno flood?
Flood insurance has paid 22 claims in San Bruno since 1978, $302K in all, or 1.3 per 1,000 homes, fewer than 71% of U.S. towns with a flood insurance record. 3 properties have flooded more than once. The most claims came from California Atmospheric River (4).
Is San Bruno 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 San Mateo County, 31% of homes in mapped flood zones carry federal flood insurance, and 1.8% of all homes do.
How much is flood insurance in San Bruno?
FEMA’s Community Rating System list shows no discount for San Bruno’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 Bruno?
By FEMA money that reached San Bruno, Severe Winter Storms, Flooding, Landslides, and Mudslides (2022): 48 households applied for aid, $81K approved, and $238K to the City of San Bruno for repairs. By flood claims, California Atmospheric River: 4 paid, $42K.
Is San Bruno at risk from earthquakes?
It is the largest share of the building damage FEMA expects here (71%), and San Bruno’s rate for it is in the top 2% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in San Bruno.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where San Bruno’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.