Santa Clara County, California
Natural disaster risk, federal disaster history and flood insurance facts.
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
- Ask whether an older house is bolted to its foundation.
- Consider separate earthquake insurance where risk is high.
- 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.
- Check that cooling works before summer.
- Know where the nearest cooling center is.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Earthquake | 99.9 | $1.2B | ||
| Inland flooding | 99.8 | $720M | ||
| Heat wave | 98.6 | $23M | ||
| Drought | 99.2 | $11M | ||
| Wildfire | 97.4 | $10M | ||
| Coastal flooding | 88.8 | $7M | ||
| Landslide | 99.7 | $5M | ||
| Tornado | 55.8 | $2M | ||
| Lightning | 46.9 | $254K | ||
| Hail | 37.5 | $197K | ||
| Tsunami | 18.5 | $142K | ||
| Strong wind | 9.4 | $81K | ||
| Winter weather | 3.1 | $2K | ||
| Avalanche | 13.0 | $17 | ||
| Volcanic activity | 15.0 | $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
Most recent
Show all 23
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.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| May 5, 1998 | F2 | Sunnyvale | 1 / 0 |
| Jan 11, 1951 | F2 | – | 0 / 0 |
| May 5, 1998 | F1 | Los Altos | 1 / 0 |
| Feb 6, 1998 | F0 | Sunnyvale | 0 / 0 |
| Dec 8, 1997 | F0 | San Jose | 0 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| Jan 19, 2017 | Hail | Los Gatos | $5M |
| Jan 19, 2017 | Hail | Agnew | $5M |
| May 5, 1998 | Tornado | Sunnyvale | $4M |
| Dec 23, 2012 | Flood | Palo Alto Arpt | $3M |
| Jan 11, 1951 | Tornado | – | $3M |
| May 5, 1998 | Tornado | Los 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 ›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
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 counties | Overall risk | Top hazard |
|---|---|---|
| Los Angeles County | Earthquake | |
| San Diego County | Inland flooding | |
| Orange County | Earthquake | |
| Riverside County | Inland flooding | |
| San Bernardino County | Inland flooding | |
| Santa Clara County | Earthquake | |
| Alameda County | Earthquake | |
| Sacramento County | Inland flooding |
Neighboring counties
| County | Overall risk | Declarations |
|---|---|---|
| Alameda County | 22 | |
| San Mateo County | 22 | |
| Stanislaus County | 18 | |
| Merced County | 17 | |
| Santa Cruz County | 32 | |
| San Benito County | 16 |
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.