Natural hazards · San Dimas

San Dimas, CA natural hazards

Most of the natural-hazard damage FEMA expects in San Dimas comes from earthquakes, and overall the risk is very high for a U.S. community. Flood insurance has paid 4 claims here since 1980. 8 federal disasters brought FEMA money into town.

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

Expected damage

How exposed is San Dimas?

Very high

vs. U.S. communities

FEMA expects yearly storm and flood damage to homes and buildings in San Dimas to be higher than in 86% of U.S. communities, mostly from earthquakes and inland flooding.

Earthquakes47%Inland flooding43%Avalanches7%Everything else3%

By hazard

What San Dimas faces

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

Earthquakes

47% of expected damage

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

Inland flooding

43% of expected damage

Well above average · higher than 86% of U.S. places

Recorded about 4 times a year in the area

Avalanches

7% of expected damage

Well below average · higher than 0% of U.S. places

Recorded about once every 69 years in the area

Lower here

TornadoesHailWinter weatherCold wavesHeat wavesWildfireLandslidesStrong windLightning

Not a risk here

Coastal floodingHurricanesIce stormsDroughtTsunamisVolcanic 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 San Dimas flood?

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

4paid claims since 1980

$10Kpaid to owners

0homes flooded more than once

19802026

Biggest named events

Pineapple Express - Southern: 2 claims, $4K

of homes in flood zones
are insured

of all homes
are insured

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

Insurance rates: Los Angeles County.

Disasters that hit San Dimas

8 federal disasters brought FEMA money here

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

Brought FEMA money into San DimasDeclared for Los Angeles County only

2025

Wildfires and Straight-Line Winds

84 households applied for aid $770 aid approved

2023

Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides

$17K to the City of San Dimas for repairs

2020

Wildfires

7 households applied for aid

2018

Wildfires

1 household applied for aid

2017

Wildfires, Flooding, Mudflows, and Debris Flows

1 household applied for aid

2007

Wildfires, Flooding, Mud Flows, and Debris Flows

1 household applied for aid

2004

Severe Storms, Flooding, Debris Flows, and Mudslides

18 households applied for aid $5K aid approved $70K to the City of San Dimas for repairs

2003

Wildfires, Flooding, Mudflow and Debris Flow Directly Related T

4 households applied for aid

Los Angeles County has had 74 natural disasters declared since 1953, most often fires and floods.

Around San Dimas

San Dimas and the towns around it

Very lowLowModerateHighVery high

Pomonamostly earthquakesVery high

La Vernemostly earthquakesVery high

Glendoramostly earthquakesVery high

Covinamostly earthquakesVery high

San Dimasmostly earthquakesVery high

Charter Oakmostly 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 Dimas covers 7 census tracts, combined by population.

Money that reached townFlood claims are matched to San Dimas’s own flood-insurance community; household aid to the registrant’s city; repair grants to the City of San Dimas. 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 Dimas total about $25.2M 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.