Mariposa County
California — Natural Disaster Risk Assessment
MediumComposite Risk Score
National percentile: 86th
Mariposa County faces medium composite natural disaster risk (NRI Risk Index score 86.4, 86th national percentile), driven primarily by landslide and wildfire exposure. Expected annual loss across all 18 hazard types is $38M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Landslide | High | 27.38 / yr | $2M |
| Wildfire | High | 0.02 / yr | $15M |
| Heat Wave | High | 6.05 / yr | $11M |
| Winter Weather | Medium | 12.67 / yr | $113K |
| Drought | Medium | 83.16 / yr | $448K |
| Riverine Flood | Low | 2.07 / yr | $8M |
| Lightning | Medium | 17.91 / yr | $302K |
| Earthquake | Low | 0.03 / yr | $433K |
| Volcanic Activity | Very Low | 0.00 / yr | $17 |
| Avalanche | Very Low | 0.01 / yr | $171 |
| Strong Wind | Very Low | 0.05 / yr | $50K |
| Hail | Very Low | 0.15 / yr | $12K |
| Tornado | Very Low | 0.12 / yr | $18K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Cold Wave | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Ice Storm | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Frequently Asked Questions
What is the overall natural disaster risk for Mariposa County?
Mariposa County has a composite FEMA National Risk Index score of 86.4 out of 100, placing it in the Medium category and the 86th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Mariposa County?
The three highest-rated hazards are Landslide (High, $2M EAL), Wildfire (High, $15M EAL), Heat Wave (High, $11M EAL). These account for most of the county's expected annual losses.
How does Mariposa County compare to other California counties?
Mariposa County ranks #43 of 58 California counties for overall natural disaster risk, with a medium rating.
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. Mariposa County's $38M EAL is a statistical average, not a guarantee for any specific year or address.