Natural hazards · Foster

Foster, CA natural hazards

Most of the natural-hazard damage FEMA expects in Foster comes from inland flooding, and overall the risk is very high for a U.S. community. Flood insurance has paid 10 claims here since 1998. 2 federal disasters brought FEMA money into town.

FEMA National Risk Index, December 2025 · OpenFEMA claims, aid & declarations

Expected damage

How exposed is Foster?

Very high

vs. U.S. communities

FEMA expects yearly storm and flood damage to homes and buildings in Foster to be higher than in 94% of U.S. communities, mostly from inland flooding and earthquakes.

Inland flooding58%Earthquakes41%Everything else1%

By hazard

What Foster faces

Each hazard’s share of the damage FEMA expects here, and how that compares with the rest of the country.

Inland flooding

58% of expected damage

Well above average · higher than 97% of U.S. places

Recorded about once a year in the area

Earthquakes

41% of expected damage

Well above average · higher than 93% of U.S. places

Lower here

Coastal floodingTornadoesHailHeat wavesWildfireLandslidesStrong windLightningDroughtTsunamis

Not a risk here

HurricanesIce stormsWinter weatherCold wavesAvalanchesVolcanic activity

Flood risk changes street by street. Check a specific address on FEMA’s flood map, and ask about flood insurance before you buy.

Flood insurance claims

Does Foster flood?

Every paid claim on a federal flood insurance policy in Foster, from FEMA’s records.

10paid claims since 1998

$210Kpaid to owners

2homes flooded more than once

19982026

Biggest named events

Pineapple Express - Southern: 2 claims, $10K
California Atmospheric River: 2 claims, $107K
Winter storm: 1 claim, $15K

Homes that flooded again and again

■ FEMA “severe repetitive loss” (0) ■ flooded 2+ times

of homes in flood zones
are insured

of all homes
are insured

No community discount. Foster 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.

Disasters that hit Foster

2 federal disasters brought FEMA money here

Disasters the President declared that paid out in Foster itself: aid to households, or repair grants to the City of Foster.

Brought FEMA money into FosterDeclared for San Mateo County only

2022

Severe Winter Storms, Flooding, Landslides, and Mudslides

18 households applied for aid $68K aid approved

2020

Wildfires

14 households applied for aid $500 aid approved

San Mateo County has had 21 natural disasters declared since 1953, most often floods and severe storms.

Around Foster

Foster and the towns around it

Very lowLowModerateHighVery high

Foster Citymostly inland floodingVery high

San Mateomostly earthquakesVery high

Haywardmostly earthquakesVery high

Redwood Citymostly earthquakesVery high

Belmontmostly earthquakesVery high

About these numbers

How to read this page

An average, not a forecastFEMA’s National Risk Index estimates the damage 18 kinds of natural hazards cause in a typical year, from decades of records and models. A quiet decade can follow a bad year.

Compared by rate“Higher than N%” compares yearly damage as a share of what’s here, so a big city isn’t rated riskier just for having more buildings. Foster covers 9 census tracts, combined by population.

Money that reached townFlood claims are matched to Foster’s own flood-insurance community; household aid to the registrant’s city; repair grants to the City of Foster. FEMA’s model follows property values, so a place that recently lost many homes can rate lower than it feels.

FEMA’s expected losses across Foster total about $35.5M a year, counting buildings, people and crops.

Sources: FEMA National Risk Index (December 2025); 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. Census tracts: U.S. Census Bureau.