St. Mary's County, Maryland
Natural disaster risk, federal disaster history and flood insurance facts.
St. Mary's County, Maryland has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 57% of US counties. It ranks 19th of 24 counties in Maryland. The costliest hazards here are inland flooding, hurricanes and strong wind. FEMA estimates about $22 million a year in expected losses, or roughly $198 per resident. Since 1977 it has been included in 16 federal disaster or emergency declarations for natural events (11 major disasters). The most recent was in January 2026 (severe winter storm). About 1 in 42 homes here carry federal flood insurance (990 policies). Since 1978, federal flood insurance has paid about $11 million on 613 claims here, including $6.7 million for floods in 2003.
FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.
Top risks in St. Mary's County
- Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
- Price a flood policy now. Most new federal policies take 30 days to start.
- Know your evacuation zone and route before June 1.
- Ask about roof age, shutters and the separate wind or hurricane deductible on your home policy.
- Secure outdoor furniture and trash bins before storms.
- Have trees near the house checked.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Inland flooding | 36.8 | $7M | ||
| Hurricane | 85.1 | $6M | ||
| Strong wind | 65.2 | $1M | ||
| Tornado | 39.4 | $1M | ||
| Heat wave | 67.3 | $1M | ||
| Coastal flooding | 63.0 | $1M | ||
| Drought | 72.3 | $1M | ||
| Earthquake | 57.2 | $670K | ||
| Cold wave | 28.8 | $654K | ||
| Lightning | 56.2 | $490K | ||
| Hail | 34.3 | $237K | ||
| Ice storm | 53.8 | $167K | ||
| Winter weather | 58.1 | $143K | ||
| Wildfire | 59.0 | $132K | ||
| Landslide | 51.4 | $2K |
Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is very low and community resilience is very high in FEMA's measures.
Federal disaster history
Recent disasters nationwide ›Declarations by decade
Federal declarations for natural events that included St. Mary's County. 2020s bar runs to November 2026.
By type
Most recent
Show all 16
Maryland also had 1 statewide declarations that did not name single counties.
Storm history since 1962
Tornado risk by county ›The National Weather Service has logged 667 storm reports in St. Mary's County since 1962, with 0 deaths and 13 injuries and about $13.8 million in reported damage. The strongest on record here was an F2 tornado on October 13, 1983.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| Oct 13, 1983 | F2 | – | 0 / 0 |
| May 8, 1984 | F1 | – | 3 / 0 |
| May 8, 1984 | F1 | – | 1 / 0 |
| Jul 1, 2025 | EF1 | Abells Wharf | 0 / 0 |
| Jul 13, 1996 | F1 | California | 0 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| Jul 29, 2023 | Thunderstorm Wind | Oaks | $5M |
| May 8, 1984 | Tornado | – | $3M |
| Jun 27, 2006 | Tornado | Chaptico | $1M |
| Sep 16, 1999 | Flash Flood | Countywide | $500K |
| May 8, 1984 | Tornado | – | $250K |
| Jun 4, 2008 | Lightning | Park Hall | $250K |
Source: NOAA Storm Events Database, county-based reports through Jul 22, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.
Hurricanes and tropical storms
Hurricane risk by county ›Since 1859, 2 hurricanes and 27 tropical storms have passed within 65 miles of the center of St. Mary's County, 12 of them since 1950. The strongest was an unnamed hurricane in 1878, with top winds near 95 mph about 39 miles away.
Strongest storms nearby
| Date | Storm | Strength | Closest |
|---|---|---|---|
| Oct 23, 1878 | Unnamed | Category 2, 95 mph | 39 mi |
| Aug 23, 1933 | Unnamed | Category 1, 75 mph | 58 mi |
| Aug 13, 1955 | Connie | Tropical storm, 70 mph | 56 mi |
| Sep 17, 1876 | Unnamed | Tropical storm, 70 mph | 50 mi |
| Aug 4, 2020 | Isaias | Tropical storm, 70 mph | 39 mi |
| Jul 13, 1996 | Bertha | Tropical storm, 70 mph | 50 mi |
Most recent storms
| Date | Storm | Strength | Closest |
|---|---|---|---|
| Jul 9, 2021 | Elsa | Tropical storm, 60 mph | 57 mi |
| Aug 4, 2020 | Isaias | Tropical storm, 70 mph | 39 mi |
| Sep 6, 2008 | Hanna | Tropical storm, 50 mph | 58 mi |
| Aug 31, 2004 | Gaston | Tropical storm, 40 mph | 62 mi |
| Jul 13, 1996 | Bertha | Tropical storm, 70 mph | 50 mi |
| Sep 25, 1992 | Danielle | Tropical storm, 65 mph | 63 mi |
Source: NOAA National Hurricane Center best-track records (HURDAT2), 1851 to 2025 for the Atlantic and 1949 to 2025 for the eastern Pacific. A storm counts if its track passed within 65 miles of the county's center while it was a tropical storm or hurricane. Strength is the storm's top sustained wind at that point, not the wind measured in the county. Older storms over the open sea were sometimes missed.
Flood insurance in St. Mary's County
Check your address flood zone ›National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.
Homes in St. Mary's County
Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 46,385 housing units.
Compare in Maryland
All 24 ›| Largest counties | Overall risk | Top hazard |
|---|---|---|
| Montgomery County | Inland flooding | |
| Prince George's County | Inland flooding | |
| Baltimore County | Inland flooding | |
| Anne Arundel County | Inland flooding | |
| Baltimore City | Inland flooding | |
| Howard County | Inland flooding | |
| Frederick County | Inland flooding | |
| Harford County | Inland flooding |
Neighboring counties
| County | Overall risk | Declarations |
|---|---|---|
| Charles County | 22 | |
| Calvert County | 22 | |
| Dorchester County | 18 | |
| Somerset County | 12 | |
| Westmoreland County, VA | 23 | |
| Northumberland County, VA | 23 |
Common questions about St. Mary's County
What is the biggest natural hazard in St. Mary's County?
Inland flooding has the highest expected yearly losses in St. Mary's County, about $7.2 million a year in FEMA's estimate. Hurricane is second at $6.4 million.
How many federal disasters has St. Mary's County had?
St. Mary's County has been included in 16 federal disaster or emergency declarations for natural events since 1977, including 11 major disasters. The most recent was Severe Winter Storm in January 2026.
Is St. Mary's County a high-risk place to live?
Its overall rating is Very Low, 19th highest of 24 in Maryland. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.
Do I need flood insurance in St. Mary's County?
Standard home insurance does not cover flooding. About 1 in 42 homes in St. Mary's County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.
How many tornadoes has St. Mary's County had?
NOAA records list 34 tornadoes in St. Mary's County since 1950. The strongest was an F2 tornado on October 13, 1983. The weather service has also logged 80 hail reports and 158 floods here.
How many hurricanes have hit St. Mary's County?
NOAA's hurricane records show 2 hurricanes and 27 tropical storms passing within 65 miles of the center of St. Mary's County. The strongest was an unnamed hurricane in 1878, with winds near 95 mph.
Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.