Willard Griffin House and Carriage House · Photo: Sanfranman59 · CC BY-SA 3.0On FEMA’s figures, Los Altos Hills faces more hazard damage per building than 88% of U.S. towns, mostly from earthquakes
On FEMA’s National Risk Index, Los Altos Hills gets a D for hazard risk: higher expected damage per building than 88% of U.S. towns, #284 of 847 in California. Most of that expected damage is earthquakes (65%), then river and rain flooding (34%). Flood insurance has paid 6 claims here since 1992.
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 Los Altos Hills 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 Los Altos Hills’ grade
Earthquakes are 65% of the building damage FEMA expects in Los Altos Hills, and Los Altos Hills’ rate of earthquakes damage is in the top 5% of U.S. census tracts. Next is river and rain flooding at 34% (higher than 56% of U.S. census tracts).
D #284 of 847 in California; higher expected damage per building than 88% of U.S. towns (21,298).
Los Altos Hills’ 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, Los Altos Hills has less expected damage per building than 67% of California towns.
In dollars, FEMA expects about $13.2M a year in losses across Los Altos Hills: $10.6M to buildings, the rest to people and crops.
Does Los Altos Hills flood? Rarely: 6 flood claims since 1992
Every paid claim on a federal flood insurance policy in Los Altos Hills, from FEMA’s records: 1.8 per 1,000 homes, fewer than 64% of the 13,809 U.S. towns with a flood insurance record.
- The Pineapple Express - Southern4 claims · $23K
Los Altos Hills isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Santa Clara County.1 federal disaster brought FEMA money to Los Altos Hills
Disasters that paid out in Los Altos Hills itself (aid to households or repair grants to the Town of Los Altos Hills), newest first, with that year’s flood claims.
- 2022Severe Winter Storms, Flooding, Landslides, and Mudslides1 households applied for aid$70K to the Town of Los Altos Hills for repairs
Santa Clara 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 3 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in Santa Clara County, 2002–2020.
Old photos of Los Altos Hills after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Los Altos Hills archive →Los Altos Hills and its neighbors
Los Altos Hills has the lowest expected damage per building of the 4 graded towns here. Tap a town to see its hazards.
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 Los Altos Hills 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 Los Altos Hills
Is Los Altos Hills at risk for natural disasters?
On FEMA’s National Risk Index, Los Altos Hills has higher expected damage per building than 88% of U.S. towns: D for hazard risk, #284 of 847 in California. Most of the expected damage is earthquakes (65%) and river and rain flooding (34%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Los Altos Hills flood?
Flood insurance has paid 6 claims in Los Altos Hills since 1992, $46K in all, or 1.8 per 1,000 homes, fewer than 64% of U.S. towns with a flood insurance record. The most claims came from Pineapple Express - Southern (4).
Is Los Altos Hills 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 Santa Clara County, 22% of homes in mapped flood zones carry federal flood insurance, and 1.7% of all homes do.
How much is flood insurance in Los Altos Hills?
FEMA’s Community Rating System list shows no discount for Los Altos Hills’ 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 Los Altos Hills?
By FEMA money that reached Los Altos Hills, Severe Winter Storms, Flooding, Landslides, and Mudslides (2022): 1 households applied for aid, $0 approved, and $70K to the Town of Los Altos Hills for repairs. By flood claims, Pineapple Express - Southern: 4 paid, $23K.
Is Los Altos Hills at risk from earthquakes?
It is the largest share of the building damage FEMA expects here (65%), and Los Altos Hills’ rate for it is in the top 5% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Los Altos Hills.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Los Altos Hills’ 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.