Riverside County, California Natural Disaster Risk
FEMA National Risk Index assessment · CA
Very HighComposite Risk Score
National percentile: 100th
Riverside County faces very high composite natural disaster risk (NRI Risk Index score 99.9, 100th national percentile), driven primarily by wildfire and riverine flood exposure. Expected annual loss across all 18 hazard types is $2.27B.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Riverside County is very high, with a National Risk Index score of 99.9 out of 100 — placing it in the 100th national percentile and among the most at-risk counties in the United States. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Most of Riverside County's expected losses come from wildfire (uncontrolled fires that spread across wildland and into communities) at Very High risk — $347M in expected annual loss and about 0.02 events per year; riverine flood (rivers and streams overflowing their banks after heavy rain or snowmelt) at Very High risk — $1.13B in expected annual loss and about 7.36 events per year; and earthquake (ground shaking from sudden movement along geologic faults) at Very High risk — $764M in expected annual loss and about 0.12 events per year. Across all hazards, FEMA estimates $2.27B in expected annual loss for a population of 2.42M.
Beyond physical exposure, Riverside County has a low social vulnerability rating (how susceptible the population is to harm) and a very low community resilience rating (its capacity to prepare for and recover from disasters). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
The county's disaster history tells the same story: Riverside County has received 66 federal disaster declarations since 1965, including 38 for fire events and 13 for flood events. The most recent was Bain Fire (fire), declared in May 2026.
Among 58 California counties, Riverside County ranks #2 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Wildfire | Very High | 0.02 / yr | $347M |
| Riverine Flood | Very High | 7.36 / yr | $1.13B |
| Earthquake | Very High | 0.12 / yr | $764M |
| Landslide | High | 21.78 / yr | $1M |
| Heat Wave | High | 13.84 / yr | $18M |
| Tornado | Medium | 0.45 / yr | $6M |
| Lightning | Medium | 13.81 / yr | $797K |
| Hail | Medium | 0.08 / yr | $990K |
| Volcanic Activity | Very Low | 0.00 / yr | $72 |
| Winter Weather | Medium | 2.40 / yr | $119K |
| Drought | Low | 57.40 / yr | $221K |
| Strong Wind | Medium | 0.23 / yr | $614K |
| Avalanche | Very Low | 0.01 / yr | $652 |
| Cold Wave | Very Low | 0.01 / yr | $139K |
| Hurricane | Very Low | 0.01 / yr | $3K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Ice Storm | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Riverside County has received 66 federal disaster declarations since 1965, most recently Bain Fire in May 2026. Most frequent causes: Fire (38), Flood (13), Severe Storm (7).
| Declared | Type | Disaster |
|---|---|---|
| May 2026 | Fire | Bain Fire |
| September 2024 | Fire | Airport Fire |
| July 2024 | Fire | Hawarden Fire |
| November 2023 | Hurricane | Tropical Storm Hilary |
| January 2023 | Flood | Severe Winter Storms, Flooding, and Mudslides |
| September 2022 | Fire | Fairview Fire |
| October 2020 | Fire | Blue Ridge Fire |
| August 2020 | Fire | Apple Fire |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
Showing the 10 most recent of 66 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Riverside County?
Riverside County has a composite FEMA National Risk Index score of 99.9 out of 100, placing it in the Very High category and the 100th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Riverside County?
The three highest-rated hazards are Wildfire (Very High, $347M EAL), Riverine Flood (Very High, $1.13B EAL), Earthquake (Very High, $764M EAL). These account for most of the county's expected annual losses.
How does Riverside County compare to other California counties?
Riverside County ranks #2 of 58 California counties for overall natural disaster risk, with a very high rating.
How many federally declared disasters has Riverside County had?
FEMA records 66 federal disaster declarations for Riverside County since 1965, most often 38 for fire events and 13 for flood events. The most recent was Bain Fire, declared in May 2026.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Riverside County's $2.27B EAL is a statistical average, not a guarantee for any specific year or address.