Ontario County
New York — Natural Disaster Risk Assessment
LowComposite Risk Score
National percentile: 64th
Ontario County faces low composite natural disaster risk (NRI Risk Index score 63.5, 64th national percentile), driven primarily by riverine flood and ice storm exposure. Expected annual loss across all 18 hazard types is $27M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Riverine Flood | Medium | 1.36 / yr | $21M |
| Ice Storm | Medium | 0.94 / yr | $379K |
| Strong Wind | Medium | 1.47 / yr | $1M |
| Drought | Medium | 2.55 / yr | $818K |
| Hurricane | Low | 0.03 / yr | $211K |
| Hail | Low | 1.51 / yr | $394K |
| Lightning | Low | 29.75 / yr | $326K |
| Landslide | Very Low | 0.24 / yr | $2K |
| Earthquake | Very Low | 0.00 / yr | $366K |
| Heat Wave | Low | 3.42 / yr | $369K |
| Tornado | Low | 0.09 / yr | $1M |
| Avalanche | Very Low | 0.01 / yr | $388 |
| Wildfire | Very Low | 0.00 / yr | $26K |
| Winter Weather | Very Low | 15.79 / yr | $19K |
| Cold Wave | Very Low | 3.11 / yr | $131K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Frequently Asked Questions
What is the overall natural disaster risk for Ontario County?
Ontario County has a composite FEMA National Risk Index score of 63.5 out of 100, placing it in the Low category and the 64th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Ontario County?
The three highest-rated hazards are Riverine Flood (Medium, $21M EAL), Ice Storm (Medium, $379K EAL), Strong Wind (Medium, $1M EAL). These account for most of the county's expected annual losses.
How does Ontario County compare to other New York counties?
Ontario County ranks #39 of 62 New York counties for overall natural disaster risk, with a low 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. Ontario County's $27M EAL is a statistical average, not a guarantee for any specific year or address.