San Joaquin County, CA
FEMA National Risk Index scores, disaster declarations & hazard data
San Joaquin County has experienced 25 federally declared disasters since 1965, most recently Severe Winter Storms, Flooding, And Mudslides in 2023. Its overall natural hazard risk is rated Relatively High — higher risk than most US counties.
San Joaquin County's highest-rated hazards are drought, earthquake, and inland flooding, with its top risk rated "Very High" by FEMA's National Risk Index. NOAA records 43 storm events in the county over the past decade. Community vulnerability is elevated (87th percentile nationally), suggesting residents may face greater difficulty recovering from major disasters.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. San Joaquin County has been designated in 25 declarations since 1965, covering 9 disaster types including flood (10), severe storm (6), biological (2).
| 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 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2017 | Flood | Severe Winter Storms, Flooding, And Mudslides |
| 2006 | Severe Storm | Severe Storms, Flooding, Mudslides, And Landslides |
| 2006 | Severe Storm | Severe Storms, Flooding, Landslides, And Mudslides |
| 2005 | Hurricane | Hurricane Katrina Evacuation |
Showing the 10 most recent of 25 total declarations since 1965.
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 | 92 | 0 | 0 | — |
| Inland Flooding | Relatively High | 97.7 | 47 | 0 | $107.6M |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Relatively High | 99.3 | 1 | — | — |
| Heat Wave | Relatively High | 97.4 | 0 | 0 | — |
| Tornado | Relatively Low | 49 | 1 | 0 | — |
| Hurricane | Not Applicable | — | 0 | 0 | — |
| Hail | Relatively Low | 54.7 | 2 | 0 | — |
| Strong Wind | Relatively Low | 38 | 0 | 0 | — |
| Winter Weather | Relatively Low | 42.4 | 0 | 0 | — |
| Ice Storm | Not Applicable | — | — | — | — |
| Cold Wave | No Rating | 0 | — | — | — |
| Lightning | Relatively High | 93.4 | 0 | 0 | — |
| Drought | Very High | 99.9 | 0 | 0 | — |
| Landslide | Very Low | 62 | 0 | 0 | — |
| Avalanche | Very Low | 2.2 | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic Activity | Very Low | 79.8 | — | — | — |
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
San Joaquin County ranks in the 87th percentile (High) 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 | 87th | High |
| Socioeconomic status | 81st | High |
| Household characteristics | 82nd | High |
| Racial & ethnic minority status | 96th | High |
| Housing type & transportation | 75th | 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 | 85th | Very High |
| Risk to homes | 84th | Very High |
| Buildings in direct exposure zone | 16.1% | — |
NOAA tracked 43 weather events in this county over 2016–2025: 6 in 2016–20 vs 37 in 2021–25 .
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 San Joaquin County?
According to the FEMA National Risk Index, the highest-risk hazards in San Joaquin County, California are drought, earthquake, and inland flooding. The county's overall natural hazard risk is rated Relatively High — higher risk than most US counties.
Has San Joaquin County received federal disaster declarations?
Yes. San Joaquin County has received 25 federal disaster declarations since 1965, including declarations in 2023. The most common disaster type on record is flood (10 declarations).
Has San Joaquin County had any FEMA disaster declarations in 2024, 2025, or 2026?
No federal disaster declarations have been recorded for San Joaquin County since the start of 2024. Its most recent declaration on record is Severe Winter Storms, Flooding, And Mudslides in 2023.
How does San Joaquin 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 Calaveras County, CA has the lowest (Relatively Moderate). San Joaquin County is rated Relatively High overall.
How is San Joaquin County's composite disaster risk index calculated?
San Joaquin 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. San Joaquin County's composite score of 99 means its overall natural hazard risk is higher than 99% of US counties.