St. Mary's County
Maryland — Natural Disaster Risk Assessment
Very LowComposite Risk Score
National percentile: 43th
St. Mary's County faces very low composite natural disaster risk (NRI Risk Index score 42.6, 43th national percentile), driven primarily by hurricane and drought exposure. Expected annual loss across all 18 hazard types is $22M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Top Hazards
All 18 Hazard Risks
| Hurricane | Medium | 0.12 / yr | $6M |
| Drought | Medium | 3.60 / yr | $1M |
| Heat Wave | Low | 6.26 / yr | $1M |
| Strong Wind | Medium | 4.69 / yr | $1M |
| Coastal Flood | Medium | 3.65 / yr | $1M |
| Wildfire | Very Low | 0.00 / yr | $132K |
| Winter Weather | Low | 6.53 / yr | $143K |
| Earthquake | Very Low | 0.00 / yr | $670K |
| Lightning | Low | 38.47 / yr | $490K |
| Ice Storm | Low | 0.49 / yr | $167K |
| Landslide | Very Low | 0.09 / yr | $2K |
| Tornado | Low | 0.45 / yr | $1M |
| Riverine Flood | Low | 2.57 / yr | $7M |
| Hail | Low | 2.64 / yr | $237K |
| Cold Wave | Low | 1.05 / yr | $654K |
| Avalanche | 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 St. Mary's County?
St. Mary's County has a composite FEMA National Risk Index score of 42.6 out of 100, placing it in the Very Low category and the 43th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in St. Mary's County?
The three highest-rated hazards are Hurricane (Medium, $6M EAL), Drought (Medium, $1M EAL), Heat Wave (Low, $1M EAL). These account for most of the county's expected annual losses.
How does St. Mary's County compare to other Maryland counties?
St. Mary's County ranks #19 of 24 Maryland 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. St. Mary's County's $22M EAL is a statistical average, not a guarantee for any specific year or address.