Petroleum County
Montana — Natural Disaster Risk Assessment
Very LowComposite Risk Score
National percentile: 1th
Petroleum County faces very low composite natural disaster risk (NRI Risk Index score 1.3, 1th national percentile), driven primarily by lightning and wildfire exposure. Expected annual loss across all 18 hazard types is $2M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Lightning | Medium | 28.75 / yr | $538K |
| Wildfire | Low | 0.00 / yr | $142K |
| Cold Wave | Low | 7.69 / yr | $505K |
| Drought | Very Low | 70.94 / yr | $2K |
| Landslide | Very Low | 0.77 / yr | $55 |
| Winter Weather | Very Low | 16.79 / yr | $11K |
| Hail | Very Low | 1.35 / yr | $31K |
| Heat Wave | Very Low | 2.90 / yr | $7K |
| Tornado | Very Low | 0.11 / yr | $5K |
| Riverine Flood | Very Low | 0.82 / yr | $398K |
| Earthquake | Very Low | 0.00 / yr | $2K |
| Strong Wind | Very Low | 0.70 / yr | $6K |
| Ice Storm | Very Low | 0.01 / yr | $353 |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | 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 Petroleum County?
Petroleum County has a composite FEMA National Risk Index score of 1.3 out of 100, placing it in the Very Low category and the 1th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Petroleum County?
The three highest-rated hazards are Lightning (Medium, $538K EAL), Wildfire (Low, $142K EAL), Cold Wave (Low, $505K EAL). These account for most of the county's expected annual losses.
How does Petroleum County compare to other Montana counties?
Petroleum County ranks #54 of 56 Montana counties for overall natural disaster risk, with a very 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. Petroleum County's $2M EAL is a statistical average, not a guarantee for any specific year or address.