John Dielmann House · Photo: BriefEdits · CC BY-SA 4.0More hazard damage per building is expected in Redwood City than in 95% of U.S. towns, mostly from earthquakes
On FEMA’s National Risk Index, Redwood City gets a D for hazard risk: higher expected damage per building than 95% of U.S. towns, #544 of 847 in California. Most of that expected damage is earthquakes (54%), then river and rain flooding (40%). Flood insurance has paid 62 claims here since 1982.
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 Redwood City’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Redwood City 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 Redwood City’s grade
Earthquakes are 54% of the building damage FEMA expects in Redwood City, and Redwood City’s rate of earthquakes damage is in the top 3% of U.S. census tracts. Coastal flooding adds 4%, at a rate in the top 2% of U.S. census tracts.
D #544 of 847 in California; higher expected damage per building than 95% of U.S. towns (21,298).
Redwood City’s residents live in 22 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, Redwood City has more expected damage per building than 64% of California towns.
In dollars, FEMA expects about $76.3M a year in losses across Redwood City: $59.4M to buildings, the rest to people and crops.
Does Redwood City flood? Sometimes: 62 flood claims since 1982
Every paid claim on a federal flood insurance policy in Redwood City, from FEMA’s records: 1.9 per 1,000 homes, fewer than 63% of the 13,809 U.S. towns with a flood insurance record.
- The California Atmospheric River34 claims · $2.1M
- The Pineapple Express - Southern9 claims · $129K
Redwood City 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.2 federal disasters brought FEMA money to Redwood City
Disasters that paid out in Redwood City itself (aid to households or repair grants to the City of Redwood City), newest first, with that year’s flood claims.
- 2022Severe Winter Storms, Flooding, Landslides, and Mudslides186 households applied for aid$606K aid approved31 flood claims paid that year
- 2020Wildfires108 households applied for aid$4K aid approved
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 Redwood City after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Redwood City archive →Redwood City and its neighbors
Redwood City is 8th of the 9 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 |
|---|---|---|---|
| Emerald Lake Hills | Dmore damage than 90% | earthquakes | — |
| Belmont | Dmore damage than 91% | earthquakes | 12 |
| San Carlos | Dmore damage than 92% | earthquakes | 48 |
| Woodside | Dmore damage than 94% | earthquakes | 10 |
| Menlo Park | Dmore damage than 94% | earthquakes | 16 |
| Atherton | Dmore damage than 95% | earthquakes | 8 |
| North Fair Oaks | Dmore damage than 95% | earthquakes | 10 |
| Redwood City | Dmore damage than 95% | earthquakes | 62 |
| 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 Redwood City 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 Redwood City
Is Redwood City at risk for natural disasters?
On FEMA’s National Risk Index, Redwood City has higher expected damage per building than 95% of U.S. towns: D for hazard risk, #544 of 847 in California. Most of the expected damage is earthquakes (54%) and river and rain flooding (40%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Redwood City flood?
Flood insurance has paid 62 claims in Redwood City since 1982, $2.5M in all, or 1.9 per 1,000 homes, fewer than 63% of U.S. towns with a flood insurance record. 3 properties have flooded more than once. The most claims came from California Atmospheric River (34).
Is Redwood City 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 Redwood City?
FEMA’s Community Rating System list shows no discount for Redwood City’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 Redwood City?
By FEMA money that reached Redwood City, Severe Winter Storms, Flooding, Landslides, and Mudslides (2022): 186 households applied for aid, $606K approved. By flood claims, California Atmospheric River: 34 paid, $2.1M.
Is Redwood City at risk from earthquakes?
It is the largest share of the building damage FEMA expects here (54%), and Redwood City’s rate for it is in the top 3% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Redwood City.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Redwood City’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.