Ernest Coxhead House · Photo: Eugene Zelenko · CC BY-SA 4.0On FEMA’s figures, San Mateo faces more hazard damage per building than 95% of U.S. towns, mostly from earthquakes
On FEMA’s National Risk Index, San Mateo 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 earthquakes (54%), then river and rain flooding (44%). Flood insurance has paid 49 claims here since 1980.
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 San Mateo’s natural hazards
From FEMA’s model and FEMA’s records, below.
What San Mateo 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 Mateo’s grade
Earthquakes are 54% of the building damage FEMA expects in San Mateo, and San Mateo’s rate of earthquakes damage is in the top 3% of U.S. census tracts. Coastal flooding adds 2%, at a rate in the top 2% of U.S. census tracts.
D− #575 of 847 in California; higher expected damage per building than 95% of U.S. towns (21,298).
San Mateo’s residents live in 28 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 Mateo has more expected damage per building than 68% of California towns.
Among the 400 U.S. cities of 100,000 or more, San Mateo has higher expected damage per building than 92% (#367 of 400). Because it is so big, its total expected yearly loss, $94.6M, is the 125th largest of those 400.
Does San Mateo flood? Sometimes: 49 flood claims since 1980
Every paid claim on a federal flood insurance policy in San Mateo, from FEMA’s records: 1.1 per 1,000 homes, fewer than 75% of the 13,809 U.S. towns with a flood insurance record.
- The California Atmospheric River14 claims · $525K
- The Winter storm1 claim · $2K
San Mateo 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.6 federal disasters brought FEMA money to San Mateo
Disasters that paid out in San Mateo itself (aid to households or repair grants to the City of San Mateo), newest first, with that year’s flood claims.
- 2023Severe Winter Storms, Straight-line Winds, Flooding, Landslides, and Mudslides$174K to the City of San Mateo for repairs3 flood claims paid that year
- 2022Severe Winter Storms, Flooding, Landslides, and Mudslides227 households applied for aid$852K aid approved$650K to the City of San Mateo for repairs12 flood claims paid that year
- 2020Wildfires902 households applied for aid$86K aid approved
- 2017Severe Winter Storms, Flooding, and Mudslides$17K to the City of San Mateo for repairs
- 2017Severe Winter Storms, Flooding, and Mudslides$8K to the City of San Mateo for repairs
- 2005Severe Storms, Flooding, Mudslides, and Landslides$37K to the City of San Mateo for repairs3 flood claims 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 Mateo after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the San Mateo archive →San Mateo and its neighbors
San Mateo is 6th of the 7 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 |
|---|---|---|---|
| Baywood Park | C−more damage than 85% | earthquakes | — |
| Hillsborough | Dmore damage than 88% | earthquakes | 8 |
| Highlands | Dmore damage than 90% | earthquakes | — |
| Belmont | Dmore damage than 91% | earthquakes | 12 |
| Burlingame | Dmore damage than 94% | earthquakes | 65 |
| San Mateo | D−more damage than 95% | earthquakes | 49 |
| Foster City | D−more damage than 97% | river and rain flooding | 10 |
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 Mateo 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 Mateo
Is San Mateo at risk for natural disasters?
On FEMA’s National Risk Index, San Mateo 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 earthquakes (54%) and river and rain flooding (44%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does San Mateo flood?
Flood insurance has paid 49 claims in San Mateo since 1980, $665K in all, or 1.1 per 1,000 homes, fewer than 75% of U.S. towns with a flood insurance record. 2 properties have flooded more than once. The most claims came from California Atmospheric River (14).
Is San Mateo 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 Mateo?
FEMA’s Community Rating System list shows no discount for San Mateo’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 Mateo?
By FEMA money that reached San Mateo, Severe Winter Storms, Flooding, Landslides, and Mudslides (2022): 227 households applied for aid, $852K approved, and $650K to the City of San Mateo for repairs. By flood claims, California Atmospheric River: 14 paid, $525K.
Is San Mateo at risk from earthquakes?
It is the largest share of the building damage FEMA expects here (54%), and San Mateo’s rate for it is in the top 3% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in San Mateo.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where San Mateo’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.