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Santa Clara County, California

Natural disaster risk, federal disaster history and flood insurance facts.

Very High overall risk
6th of 58highest risk in California
$2Bexpected losses a year
23federal declarations
1 in 59homes with flood insurance
Photo: Michael from San Jose, California, USA, CC BY 2.0

Santa Clara County, California has a very high overall risk from natural hazards in FEMA's National Risk Index. Its risk score is in the top 1% of US counties. It ranks 6th of 58 counties in California. The costliest hazards here are earthquakes, inland flooding and heat waves. FEMA estimates about $2.0 billion a year in expected losses, or roughly $1,016 per resident. Since 1977 it has been included in 23 federal disaster or emergency declarations for natural events (15 major disasters). The most recent was in April 2023 (severe winter storms, straight-line winds, flooding, landslides and mudslides). About 1 in 59 homes here carry federal flood insurance (8,141 policies). Since 1978, federal flood insurance has paid about $25 million on 1,630 claims here, including $9.5 million for floods in 1998.

FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.

Top risks in Santa Clara County

Earthquake

Very High
$1.2 billion a yearExpected losses. Damaging events about once every 5 years.
  • Ask whether an older house is bolted to its foundation.
  • Consider separate earthquake insurance where risk is high.
$720 million a yearExpected losses. Damaging events about 2 times a year.
  • Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
  • Price a flood policy now. Most new federal policies take 30 days to start.
$23.5 million a yearExpected losses. Damaging events about 8 times a year.
  • Check that cooling works before summer.
  • Know where the nearest cooling center is.
HazardRatingScoreExpected loss a year
EarthquakeVery High99.9
$1.2B
Inland floodingVery High99.8
$720M
Heat waveHigh98.6
$23M
DroughtHigh99.2
$11M
WildfireModerate97.4
$10M
Coastal floodingHigh88.8
$7M
LandslideHigh99.7
$5M
TornadoLow55.8
$2M
LightningLow46.9
$254K
HailLow37.5
$197K
TsunamiVery Low18.5
$142K
Strong windVery Low9.4
$81K
Winter weatherVery Low3.1
$2K
AvalancheVery Low13.0
$17
Volcanic activityVery Low15.0
$0

Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is very low and community resilience is relatively high in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

Federal declarations for natural events that included Santa Clara County. 2020s bar runs to November 2026.

By type

Flood6
Fire6
Severe Storm6
Drought1
Coastal Storm1
Earthquake1

Most recent

Apr 3, 2023Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and MudslidesMajor disaster
Mar 10, 2023Severe Winter Storms, Flooding, Landslides, and MudslidesEmergency
Jan 14, 2023Severe Winter Storms, Flooding, Landslides, and MudslidesMajor disaster
Jan 9, 2023Severe Winter Storms, Flooding, and MudslidesEmergency
Aug 22, 2020WildfiresMajor disaster
Aug 21, 2020Scu Ligtning Complex FireFire management
Apr 1, 2017Severe Winter Storms, Flooding, and MudslidesMajor disaster
Feb 14, 2017Severe Winter Storms, Flooding, and MudslidesMajor disaster
Jun 28, 2008WildfiresEmergency
May 22, 2008Summit FireFire management
Show all 23
Sep 13, 2005Hurricane Katrina EvacuationEmergency
Sep 25, 2002Croy FireFire management
Feb 9, 1998Severe Winter Storms and FloodingMajor disaster
Jan 4, 1997Severe Storms, Flooding, Mud and LandslidesMajor disaster
Mar 12, 1995Severe Winter Storms, Flooding Landslides, Mud FlowMajor disaster
Jan 10, 1995Severe Winter Storms, Flooding, Landslides, Mud FlowsMajor disaster
Feb 11, 1991Severe FreezeMajor disaster
Oct 18, 1989Loma Prieta EarthquakeMajor disaster
Feb 21, 1986Severe Storms & FloodingMajor disaster
Jul 18, 1985Grass, Wildlands, & Forest FiresMajor disaster
Feb 9, 1983Coastal Storms, Floods, Slides & TornadoesMajor disaster
Jan 7, 1982Severe Storms, Flood, Mudslides & High TideMajor disaster
Jan 20, 1977DroughtEmergency

California also had 35 statewide declarations that did not name single counties.

Storm history since 1951

Tornado risk by county ›

The National Weather Service has logged 259 storm reports in Santa Clara County since 1951, with 3 deaths and 8 injuries and about $19.9 million in reported damage. The strongest on record here was an F2 tornado on May 5, 1998 near Sunnyvale.

6tornadoes
35hail reports, largest 1 inches
8damaging thunderstorm winds
167floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
May 5, 1998F2Sunnyvale1 / 0
Jan 11, 1951F2–0 / 0
May 5, 1998F1Los Altos1 / 0
Feb 6, 1998F0Sunnyvale0 / 0
Dec 8, 1997F0San Jose0 / 0

Most damaging storms

DateTypeNearDamage
Jan 19, 2017HailLos Gatos$5M
Jan 19, 2017HailAgnew$5M
May 5, 1998TornadoSunnyvale$4M
Dec 23, 2012FloodPalo Alto Arpt$3M
Jan 11, 1951Tornado–$3M
May 5, 1998TornadoLos Altos$300K

Source: NOAA Storm Events Database, county-based reports through Jan 5, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.

Flood insurance in Santa Clara County

Check your address flood zone ›
1.7%of homes have federal flood insurance (8,141 policies)
21.6%of homes in mapped high-risk flood zones are insured
$24.6 millionpaid on 1,630 flood claims since 1978
1998costliest year, with $9.5 million paid

National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.

Homes in Santa Clara County

$1.5 millionmedian home value (California $734,700, US $332,700)
1975median year homes were built (California 1976, US 1980)
60%of homes built before 1980, before many modern wind, quake and flood building rules
2.8%of homes are mobile homes, which are the least safe in tornadoes and high winds

Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 698,837 housing units.

Compare in California

All 58 ›
Largest countiesOverall riskTop hazard
Los Angeles CountyVery HighEarthquake
San Diego CountyVery HighInland flooding
Orange CountyVery HighEarthquake
Riverside CountyVery HighInland flooding
San Bernardino CountyVery HighInland flooding
Santa Clara CountyVery HighEarthquake
Alameda CountyVery HighEarthquake
Sacramento CountyHighInland flooding

Neighboring counties

CountyOverall riskDeclarations
Alameda CountyVery High22
San Mateo CountyHigh22
Stanislaus CountyHigh18
Merced CountyHigh17
Santa Cruz CountyHigh32
San Benito CountyModerate16

Common questions about Santa Clara County

What is the biggest natural hazard in Santa Clara County?

Earthquake has the highest expected yearly losses in Santa Clara County, about $1.2 billion a year in FEMA's estimate. Inland flooding is second at $720 million.

How many federal disasters has Santa Clara County had?

Santa Clara County has been included in 23 federal disaster or emergency declarations for natural events since 1977, including 15 major disasters. The most recent was Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides in April 2023.

Is Santa Clara County a high-risk place to live?

Its overall rating is Very High, 6th highest of 58 in California. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.

Do I need flood insurance in Santa Clara County?

Standard home insurance does not cover flooding. About 1 in 59 homes in Santa Clara County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.

How many tornadoes has Santa Clara County had?

NOAA records list 6 tornadoes in Santa Clara County since 1950. The strongest was an F2 tornado on May 5, 1998 near Sunnyvale. The weather service has also logged 35 hail reports and 167 floods here.

Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.