Santa Clara County, CA
FEMA National Risk Index scores, disaster declarations & hazard data
Santa Clara County has experienced 25 federally declared disasters since 1977, most recently Severe Winter Storms, Flooding, And Mudslides in 2023. Its overall natural hazard risk is rated Very High — among the most at-risk counties in the country.
Santa Clara County's highest-rated hazards are earthquake, inland flooding, and landslide, with its top risk rated "Very High" by FEMA's National Risk Index. Recorded storm events have decreased 73% over the past five years compared to the prior five-year period.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Santa Clara County has been designated in 25 declarations since 1977, covering 9 disaster types including fire (6), severe storm (6), flood (6).
| Year | Type | Event name |
|---|---|---|
| 2023 | Severe Storm | Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, And Mudslides |
| 2023 | Flood | Severe Winter Storms, Flooding, Landslides, And Mudslides |
| 2023 | Flood | Severe Winter Storms, Flooding, Landslides, And Mudslides |
| 2023 | Flood | Severe Winter Storms, Flooding, And Mudslides |
| 2020 | Fire | Wildfires |
| 2020 | Fire | Scu Ligtning Complex Fire |
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2017 | Flood | Severe Winter Storms, Flooding, And Mudslides |
| 2017 | Severe Storm | Severe Winter Storms, Flooding, And Mudslides |
Showing the 10 most recent of 25 total declarations since 1977.
Source: FEMA OpenFEMA Disaster Declarations Summaries. A single disaster can produce more than one record per county. Data current through September 2026.
Risk by hazard type
| Hazard | Risk rating | Risk score | Recorded events | Deaths | Prop. damage |
|---|---|---|---|---|---|
| Wildfire | Relatively Moderate | 97.4 | 0 | 0 | — |
| Inland Flooding | Very High | 99.8 | 117 | 1 | $5K |
| Coastal Flooding | Relatively High | 88.8 | 0 | 0 | — |
| Earthquake | Very High | 99.9 | 158 | — | — |
| Heat Wave | Relatively High | 98.6 | 1 | 0 | — |
| Tornado | Relatively Low | 55.8 | 0 | 0 | — |
| Hurricane | Not Applicable | — | 0 | 0 | — |
| Hail | Relatively Low | 37.5 | 33 | 0 | $10.0M |
| Strong Wind | Very Low | 9.4 | 0 | 0 | — |
| Winter Weather | Very Low | 3.1 | 0 | 0 | — |
| Ice Storm | Not Applicable | — | — | — | — |
| Cold Wave | No Rating | 0 | — | — | — |
| Lightning | Relatively Low | 46.9 | 5 | 0 | — |
| Drought | Relatively High | 99.2 | 0 | 0 | — |
| Landslide | Relatively High | 99.7 | 24 | 0 | — |
| Avalanche | Very Low | 13 | — | — | — |
| Tsunami | Very Low | 18.5 | — | — | — |
| Volcanic Activity | Very Low | 15 | — | — | — |
Scores are 0–100 percentiles relative to all US counties — higher means more exposed, not that a disaster is likely this year. Event counts: NOAA Storm Events 2016–2026; earthquake counts from USGS ComCat (M3.0+, 1996–2026). See the methodology page for details.
Community vulnerability
Santa Clara County ranks in the 36th percentile (Low) for community vulnerability — a measure of how hard disaster impacts tend to hit residents. Higher vulnerability means more displacement, worse health outcomes, and slower recovery after a disaster.
| SVI theme | Percentile | Vulnerability level |
|---|---|---|
| Overall | 36th | Low |
| Socioeconomic status | 13th | Very low |
| Household characteristics | 9th | Very low |
| Racial & ethnic minority status | 96th | High |
| Housing type & transportation | 82nd | High |
Source: CDC/ATSDR Social Vulnerability Index 2022. Percentiles compare counties nationally — higher means more vulnerable relative to other counties. See CDC SVI for full methodology.
Future risk outlook
| Wildfire metric | National percentile | Level |
|---|---|---|
| Burn probability | 97th | Very High |
| Risk to homes | 97th | Very High |
| Buildings in direct exposure zone | 8.2% | — |
NOAA tracked 178 weather events in this county over 2016–2025: 140 in 2016–20 vs 38 in 2021–25 (-73% — frequency decreasing).
Wildfire: USDA Forest Service Wildfire Risk to Communities (RDS-2020-0016-2) — modeled values, not annual forecasts. See wildfirerisk.org. Inland flood and heat projections pending data availability; coastal sea-level projections are available for select coastal counties below — see the data page.
Nearby counties
Frequently asked questions
What natural hazards pose the greatest risk in Santa Clara County?
According to the FEMA National Risk Index, the highest-risk hazards in Santa Clara County, California are earthquake, inland flooding, and landslide. The county's overall natural hazard risk is rated Very High — among the most at-risk counties in the country.
Has Santa Clara County received federal disaster declarations?
Yes. Santa Clara County has received 25 federal disaster declarations since 1977, including declarations in 2023. The most common disaster type on record is fire (6 declarations).
Has Santa Clara County had any FEMA disaster declarations in 2024, 2025, or 2026?
No federal disaster declarations have been recorded for Santa Clara County since the start of 2024. Its most recent declaration on record is Severe Winter Storms, Flooding, And Mudslides in 2023.
How does Santa Clara County's natural hazard risk compare to nearby counties?
Among neighboring counties, Alameda County, CA has the highest overall natural hazard risk (Very High) and Merced County, CA has the lowest (Relatively High). Santa Clara County is rated Very High overall.
How is Santa Clara County's composite disaster risk index calculated?
Santa Clara County's composite disaster risk index — officially FEMA's National Risk Index (NRI) — scores every US county on a 0–100 percentile scale across 18 natural hazard types, factoring in expected annual loss, social vulnerability, and community resilience. Santa Clara County's composite score of 100 means its overall natural hazard risk is higher than 100% of US counties.