Natural hazards · San Lorenzo

San Lorenzo, CA natural hazards

Most of the natural-hazard damage FEMA expects in San Lorenzo comes from earthquakes, and overall the risk is very high for a U.S. community. Flood insurance has paid 2 claims here since 2002. 1 federal disaster brought FEMA money into town.

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

Expected damage

How exposed is San Lorenzo?

Very high

vs. U.S. communities

FEMA expects yearly storm and flood damage to homes and buildings in San Lorenzo to be higher than in 91% of U.S. communities, mostly from earthquakes and inland flooding.

Earthquakes73%Inland flooding26%Everything else1%

By hazard

What San Lorenzo faces

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

Earthquakes

73% of expected damage

Well above average · higher than 98% of U.S. places

Inland flooding

26% of expected damage

Well above average · higher than 81% of U.S. places

Recorded about 2 times a year in the area

Lower here

Coastal floodingTornadoesHailHeat wavesWildfireLandslidesStrong windLightningDroughtTsunamisVolcanic activity

Not a risk here

HurricanesIce stormsWinter weatherCold wavesAvalanches

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 San Lorenzo flood?

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

2paid claims since 2002

$32Kpaid to owners

0homes flooded more than once

20022026

Biggest named events

California Atmospheric River: 1 claim, $10K

of homes in flood zones
are insured

of all homes
are insured

No community discount. San Lorenzo isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.

Insurance rates: Alameda County.

Disasters that hit San Lorenzo

1 federal disaster brought FEMA money here

Disasters the President declared that paid out in San Lorenzo itself: aid to households, or repair grants to San Lorenzo.

Brought FEMA money into San LorenzoDeclared for Alameda County only

2022

Severe Winter Storms, Flooding, Landslides, and Mudslides

10 households applied for aid

Alameda County has had 20 natural disasters declared since 1953, most often severe storms and floods.

Around San Lorenzo

San Lorenzo and the towns around it

Very lowLowModerateHighVery high

San Leandromostly earthquakesVery high

Haywardmostly earthquakesVery high

San Lorenzomostly earthquakesVery high

Cherrylandmostly earthquakesVery high

Ashlandmostly 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. San Lorenzo covers 6 census tracts, combined by population.

Money that reached townFlood claims are matched to San Lorenzo’s own flood-insurance community (here, the census tracts inside it); household aid to the registrant’s city; repair grants to San Lorenzo. 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 San Lorenzo total about $21.0M 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.