Riverside County, California: Natural Disaster Risk and History
Riverside County, California has a Very High natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 99.9 out of 100, higher than about 99% of US counties, with wildfires, inland (river and flash) flooding and earthquakes scoring highest of its 18 hazards and $2.3 billion a year in expected losses.
OpenFEMA lists 64 federal disaster declarations that included Riverside County since 1965, not counting 2 for COVID-19; the latest is FM-5636-CA (Bain Fire, declared 20 May 2026). NOAA's Storm Prediction Center recorded 27 tornadoes touching Riverside County from 1950 to 2025.
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Population 2,416,838 Buildings worth $470 billion Area 7,377 sq mi Risk rank in California 2 of 58 FIPS 06065
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Wildfire | Very High | 100.0 | $347 million | about once every 52 years | — |
| Inland flooding | Very High | 99.9 | $1.1 billion | about 7.4 a year | 206 |
| Earthquake | Very High | 99.8 | $764 million | about once every 8.5 years | — |
| Landslide | Relatively High | 98.7 | $1.1 million | about 22 a year | — |
| Heat wave | Relatively High | 98.5 | $18 million | about 14 a year | 115 |
| Tornado | Relatively Moderate | 86.7 | $5.9 million | about once every 2.2 years | 23 |
| Lightning | Relatively Moderate | 81.5 | $797,037 | about 14 a year | 394,130 strikes |
| Hail | Relatively Moderate | 81.4 | $989,710 | about once every 12 years | 3.2 |
| Winter weather | Relatively Moderate | 66.8 | $118,964 | about 2.4 a year | 45 |
| Volcanic activity | Very Low | 66.8 | $72 | rarer than once in 1,000 years | 1 |
| Drought | Relatively Low | 55.7 | $220,571 | about 57 a year | 3,696 |
| Strong wind | Relatively Moderate | 52.7 | $613,956 | about once every 4.4 years | 9 |
| Avalanche | Very Low | 51.6 | $652 | about once every 100 years | 0 |
| Cold wave | Very Low | 13.9 | $138,854 | about once every 80 years | 0.2 |
| Hurricane | Very Low | 12.0 | $2,672 | about once every 70 years | 3 |
| 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 64
Most common: Fire 38, Flood 13, Severe Storm 7, Hurricane 2.
| Decade | Declarations | Incident types |
|---|---|---|
| 1960s | 3 | Flood ×3 |
| 1970s | 3 | Flood ×3 |
| 1980s | 5 | Flood ×3, Coastal Storm, Fire |
| 1990s | 8 | Severe Storm ×3, Fire ×2, Flood, Earthquake, Freezing |
| 2000s | 23 | Fire ×19, Severe Storm ×2, Freezing, Hurricane |
| 2010s | 14 | Fire ×10, Severe Storm ×2, Flood ×2 |
| 2020s | 8 | Fire ×6, Hurricane, Flood |
The last 10
Widest declarations that included Riverside 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, Flooding, Landslides, Mud Flows (1995, DR-1044-CA): 42 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 27
| Tornadoes touching the county | 27 |
|---|---|
| Strongest-rated | (E)F3 ×1 |
| Peak month | August (6) |
| Deadliest | 6 Aug 2015, EF1, 4 mi path, 0 killed, 2 injured |
| Longest path | 21 Jan 2010, EF0, 14.3 mi path |
| Most recent | 8 Oct 2022, EF0, 1.6 mi path |
| Deaths / injuries on those paths | 0 / 4 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 20 | 4 | 1 | 1 | 0 | 0 | 1 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 1 | 0 | 2 | 2 | 4 | 9 | 7 | 2 |
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 Riverside County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Riverside County (this page) | — | Very High | 99.9 | Wildfire |
| Imperial County | 98 km | Relatively High | 96.5 | Earthquake |
| San Diego County | 104 km | Very High | 99.7 | Wildfire |
| San Bernardino County | 124 km | Very High | 99.8 | Landslide |
| Orange County | 163 km | Very High | 99.8 | Earthquake |
| La Paz County, AZ | 186 km | Relatively Moderate | 83.5 | Inland flooding |
Nearest by distance between county centres. Every county in California, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively Low 33.3 |
|---|---|
| Community resilience | Very Low 13.0 |
| Community risk factor | 1.02 |
| Expected annual loss, all hazards | $2.3 billion |
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 Riverside County's main hazards
- Right now: National Weather Service alerts for California · all official warnings on Global Incident Tracker.
- Wildfire: US wildfires now · Wildfire smoke: what protects you
- Inland flooding: Flood safety: why shallow water kills · Floods recorded
- Earthquake: Earthquakes today · Earthquake safety guide
- 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 Riverside County
What natural disasters is Riverside County, California most at risk from?
Riverside County, California has a Very High natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 99.9 out of 100, higher than about 99% of US counties, with wildfires, inland (river and flash) flooding and earthquakes scoring highest of its 18 hazards and $2.3 billion a year in expected losses.
How many federal disaster declarations has Riverside County had?
OpenFEMA lists 64 federal disaster declarations that included Riverside County since 1965, not counting 2 for COVID-19; the latest is FM-5636-CA (Bain Fire, declared 20 May 2026). Another 30 California declarations were made statewide without a county list.
How many tornadoes have hit Riverside County?
NOAA's Storm Prediction Center recorded 27 tornadoes touching Riverside County from 1950 to 2025. The deadliest: 6 Aug 2015, EF1, 4 mi path, 0 killed, 2 injured (deaths and injuries are for the whole path).
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.