Imperial County, California: Natural Disaster Risk and History
Imperial County, California has a Relatively High natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 96.5 out of 100, higher than about 96% of US counties, with earthquakes, inland (river and flash) flooding and heat waves scoring highest of its 18 hazards and $148 million a year in expected losses.
OpenFEMA lists 13 federal disaster declarations that included Imperial County since 1976, not counting 2 for COVID-19; the latest is DR-4750-CA (Tropical Storm Hilary, declared 21 November 2023). NOAA's Storm Prediction Center recorded 7 tornadoes touching Imperial County from 1950 to 2025.
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Population 179,319 Buildings worth $38 billion Area 4,526 sq mi Risk rank in California 25 of 58 FIPS 06025
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Earthquake | Relatively High | 99.2 | $101 million | about once every 6.6 years | — |
| Inland flooding | Relatively High | 94.1 | $43 million | about 1.5 a year | 43 |
| Heat wave | Relatively Moderate | 94.0 | $3.1 million | about 17 a year | 107 |
| Volcanic activity | Relatively Low | 86.0 | $2,372 | rarer than once in 1,000 years | 1 |
| Wildfire | Relatively Low | 76.0 | $183,745 | rarer than once in 1,000 years | — |
| Drought | Relatively Moderate | 69.2 | $320,568 | about 39 a year | 1,218 |
| Strong wind | Relatively Moderate | 54.7 | $401,060 | about once every 3.6 years | 11 |
| Landslide | Very Low | 41.2 | $459 | about 6.5 a year | — |
| Hurricane | Very Low | 22.3 | $4,743 | about once every 54 years | 6 |
| Hail | Very Low | 20.2 | $45,806 | about once every 19 years | 2.1 |
| Lightning | Very Low | 16.0 | $34,703 | about 11 a year | 66,310 strikes |
| Tornado | Very Low | 11.4 | $53,237 | about once every 10 years | 4 |
| Winter weather | Very Low | 1.1 | — | rarer than once in 1,000 years | 0 |
| Cold wave | No Rating | 0.0 | — | — | 0 |
| Avalanche | Not Applicable | — | — | — | — |
| Coastal flooding | Not Applicable | — | — | — | — |
| Ice storm | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
Score: FEMA's percentile among US counties that face the hazard (higher = more risk). Expected loss: FEMA's modelled average yearly loss to buildings, people (as a statistical value) and crops. How often: FEMA's annualised frequency of the hazard in the county; for some hazards it counts event-days, so it is a rough guide, not a forecast. "Not Applicable" means FEMA does not model that hazard here.
Federal disaster declarations 13
Most common: Flood 4, Severe Storm 3, Hurricane 2, Earthquake 2.
| Decade | Declarations | Incident types |
|---|---|---|
| 1970s | 2 | Earthquake, Flood |
| 1980s | 1 | Flood |
| 1990s | 3 | Severe Storm, Flood, Freezing |
| 2000s | 2 | Freezing, Hurricane |
| 2010s | 2 | Earthquake, Severe Storm |
| 2020s | 3 | Hurricane, Severe Storm, Flood |
The last 10
Widest declarations that included Imperial County
- Hurricane Katrina Evacuation (2005, EM-3248-CA): 58 California counties designated.
- Severe Winter Storms, Flooding Landslides, Mud Flow (1995, DR-1046-CA): 57 California counties designated.
- Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides (2023, DR-4699-CA): 46 California counties designated.
Named storms in its declarations: Tropical Storm Hilary (2023), Hurricane Katrina (2005), Tropical Storm Kathleen (1976).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. California also had 30 statewide declarations with no county list.
Tornado record since 1950 7
| Tornadoes touching the county | 7 |
|---|---|
| Strongest-rated | (E)F1 ×2 |
| Peak month | July (2) |
| Deadliest | — |
| Longest path | 30 Aug 2000, F0, 3 mi path |
| Most recent | 30 Aug 2000, F0, 3 mi path |
| Deaths / injuries on those paths | 0 / 0 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 5 | 2 | 0 | 0 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 0 | 2 | 1 | 0 | 3 | 1 | 0 | 0 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How Imperial County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Imperial County (this page) | — | Relatively High | 96.5 | Earthquake |
| Riverside County | 98 km | Very High | 99.9 | Wildfire |
| San Diego County | 127 km | Very High | 99.7 | Wildfire |
| Yuma County, AZ | 140 km | Relatively Moderate | 92.6 | Earthquake |
| La Paz County, AZ | 150 km | Relatively Moderate | 83.5 | Inland flooding |
| San Bernardino County | 214 km | Very High | 99.8 | Landslide |
Nearest by distance between county centres. Every county in California, ranked.
Vulnerability and resilience
| Social vulnerability | Very High 85.1 |
|---|---|
| Community resilience | Very Low 2.4 |
| Community risk factor | 1.63 |
| Expected annual loss, all hazards | $148 million |
FEMA scales expected losses up where social vulnerability is high (people who may find it harder to prepare, evacuate or recover) and down where community resilience is high. A factor above 1 raises the risk score. For social vulnerability a high rating is worse; for resilience a high rating is better.
Prepare for Imperial County's main hazards
- Right now: National Weather Service alerts for California · all official warnings on Global Incident Tracker.
- Earthquake: Earthquakes today · Earthquake safety guide
- Inland flooding: Flood safety: why shallow water kills · Floods recorded
- Heat wave: Heatstroke warning signs
- Your property's flood zone: FEMA Flood Map Service Center ↗ — this page cannot tell you that.
- Official preparedness guidance: Ready.gov ↗ and your county emergency management office.
What this page shows, and what it misses
FEMA's National Risk Index rates a whole county against every other US county; it is a planning-level estimate for nationwide comparison, not a flood-zone map and not a substitute for a local risk assessment or the risk to one home. Declarations are presidential disaster, emergency and fire management declarations that named this county; state declarations and SBA or USDA designations are not included. Tornadoes are counted when the county is one of up to four listed on the track; 670 tornadoes that crossed a state line carry no county list in NOAA's file and are left out.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. This product uses the Federal Emergency Management Agency’s National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about Imperial County
What natural disasters is Imperial County, California most at risk from?
Imperial County, California has a Relatively High natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 96.5 out of 100, higher than about 96% of US counties, with earthquakes, inland (river and flash) flooding and heat waves scoring highest of its 18 hazards and $148 million a year in expected losses.
How many federal disaster declarations has Imperial County had?
OpenFEMA lists 13 federal disaster declarations that included Imperial County since 1976, not counting 2 for COVID-19; the latest is DR-4750-CA (Tropical Storm Hilary, declared 21 November 2023). Another 30 California declarations were made statewide without a county list.
How many tornadoes have hit Imperial County?
NOAA's Storm Prediction Center recorded 7 tornadoes touching Imperial County from 1950 to 2025.
Is the National Risk Index a flood zone map?
No. The National Risk Index is a planning-level estimate for a whole county, built for nationwide comparison. It does not tell you the flood zone or the risk of a single property: for that, look up the address on FEMA's Flood Map Service Center (msc.fema.gov) and ask your local floodplain manager.