Natural hazards · Antioch

Antioch, CA natural hazards

Most of the natural-hazard damage FEMA expects in Antioch comes from earthquakes, and overall the risk is high for a U.S. community. Flood insurance has paid 59 claims here since 1982. 2 federal disasters brought FEMA money into town.

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

Expected damage

How exposed is Antioch?

High

vs. U.S. communities

FEMA expects yearly storm and flood damage to homes and buildings in Antioch to be higher than in 79% of U.S. communities, mostly from earthquakes and inland flooding.

Earthquakes56%Inland flooding40%Everything else5%

By hazard

What Antioch faces

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

Earthquakes

56% of expected damage

Well above average · higher than 92% of U.S. places

Inland flooding

40% of expected damage

Above average · higher than 71% of U.S. places

Recorded about once a year in the area

Lower here

Coastal floodingTornadoesHailWinter weatherHeat wavesWildfireLandslidesStrong windLightningDroughtTsunamisVolcanic activity

Not a risk here

HurricanesIce stormsCold 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 Antioch flood?

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

59paid claims since 1982

$3.0Mpaid to owners

11homes flooded more than once

19822026

Biggest named events

Pineapple Express - Southern: 8 claims, $218K
California Atmospheric River: 6 claims, $684K

Homes that flooded again and again

■ FEMA “severe repetitive loss” (3) ■ flooded 2+ times

of homes in flood zones
are insured

of all homes
are insured

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

Insurance rates: Contra Costa County.

What’s been done with FEMA grants

1buildings floodproofed

Disasters that hit Antioch

2 federal disasters brought FEMA money here

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

Brought FEMA money into AntiochDeclared for Contra Costa County only

2022

Severe Winter Storms, Flooding, Landslides, and Mudslides

138 households applied for aid $115K aid approved $552K to the City of Antioch for repairs

2005

Severe Storms, Flooding, Mudslides, and Landslides

2 households applied for aid $9K to the City of Antioch for repairs

Contra Costa County has had 17 natural disasters declared since 1953, most often floods and severe storms.

Around Antioch

Antioch and the towns around it

Very lowLowModerateHighVery high

Oakleymostly inland floodingVery high

Pittsburgmostly earthquakesVery high

Brentwoodmostly inland floodingVery high

Antiochmostly earthquakesHigh

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. Antioch covers 20 census tracts, combined by population.

Money that reached townFlood claims are matched to Antioch’s own flood-insurance community; household aid to the registrant’s city; repair grants to the City of Antioch. 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 Antioch total about $49.3M 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.