Maryland Environment & Hazard Risk
1 county rated high or very high risk. 24,003 storm events since 1996, #34 among states.
- Expected yearly loss
- $1.06B
- $172 per person
- Storm events since 1996
- 24,003
- Most often thunderstorm wind
- Flood insurance policies
- 33,232
- $340M in claims paid
- Superfund sites
- 26
- 162 toxic release facilities
Risk by county
FEMA National Risk Index rating, highest risk first
| County | Overall risk | Top hazard | Flood policies | Flood claims paid |
|---|---|---|---|---|
| Baltimore city | High | Heat wave | 678 | $26.74M |
| Baltimore County | Moderate | Winter weather | 3,097 | $70.27M |
| Prince George's County | Moderate | Winter weather | 2,249 | $7.86M |
| Montgomery County | Moderate | Winter weather | 2,029 | $4.77M |
| Anne Arundel County | Moderate | Winter weather | 4,442 | $53.1M |
| Frederick County | Low | Winter weather | 501 | $2.07M |
| Harford County | Low | Winter weather | 534 | $3.96M |
| Howard County | Low | Winter weather | 816 | $15.78M |
| Washington County | Low | Drought | 280 | $3.93M |
| Worcester County | Low | Hurricane | 7,870 | $19.47M |
| Wicomico County | Low | Hurricane | 488 | $5.96M |
| Somerset County | Low | Coastal flooding | 1,649 | $15.13M |
| Carroll County | Low | Strong wind | 177 | $1.21M |
| Cecil County | Low | Drought | 533 | $14.34M |
| Allegany County | Low | Landslide | 135 | $5.41M |
| Dorchester County | Low | Coastal flooding | 1,382 | $21.7M |
| Caroline County | Low | Drought | 158 | $1.38M |
| Charles County | Low | Heat wave | 547 | $6.53M |
| St. Mary's County | Very Low | Hurricane | 990 | $11.23M |
| Talbot County | Very Low | Drought | 1,771 | $14.17M |
| Queen Anne's County | Very Low | Drought | 1,675 | $15.37M |
| Calvert County | Very Low | Hurricane | 699 | $9.59M |
| Kent County | Very Low | Drought | 460 | $8.93M |
| Garrett County | Very Low | Landslide | 72 | $1.12M |
Costliest hazards
Expected annual loss in Maryland, all counties combined
- Heat wave$140M/yr · 4 counties high
- Hurricane$128M/yr
- Tornado$53.81M/yr · 2 counties high
- Earthquake$49.94M/yr
- Cold wave$49.55M/yr · 2 counties high
- Strong wind$40.25M/yr · 8 counties high
- Coastal flooding$27.65M/yr · 3 counties high
- Drought$24.73M/yr · 4 counties high
- Lightning$22.34M/yr · 7 counties high
- Winter weather$14.03M/yr · 10 counties high
Storm events by type
Since 1996: 236 deaths, $1.52B in property and crop damage
- Thunderstorm Wind7,687 · 16 deaths
- Winter Weather2,820 · 9 deaths
- Flash Flood1,760 · 22 deaths
- Flood1,471 · 2 deaths
- Hail1,382
- Winter Storm1,215 · 6 deaths
- Dense Fog1,086 · 2 deaths
- Heat1,010 · 111 deaths
- Strong Wind749 · 2 deaths
- Heavy Rain744 · 4 deaths
- High Wind540 · 4 deaths
- Frost/Freeze531
Events per year
Most damaging storms
Since 2017, ranked by deaths, injuries and damage
- Excessive Heat07/03/2018
Southern Baltimore
8 deaths
What happened
Heat indices around 110 degrees were reported. The Maryland Department of Health reported 8 fatalities due to the excessive heat in Baltimore City. The fatalities occurred during the week of July 3rd to July 9th.
- Flash Flood05/16/2018
Ft Detrick, Frederick County
$43.2M damage
What happened
Significant flash flooding occurred during the evening of May 15th from the city of Frederick southwestward toward Braddock Heights and Jefferson. The amount of damage shown here is total damage not already accounted for in other reports.
- Heat07/16/2018
Southern Baltimore
3 deaths
What happened
Heat indices were close to 100 degrees. The Maryland Department of Health reported three fatalities due to the heat during the week of July 10th through July 16th.
- Thunderstorm Wind78 kt wind08/07/2023
Cranberry Station, Carroll County
2 injured, $20M damage
What happened
Thousands of trees, branches and wires blew down near and north of Westminster. 30 utility poles snapped along MD-97/MD-140 Baltimore Boulevard near Gorsuch Road, with live wires trapping several people in their vehicles for a few hours; two people were injured. Dozens of roads in the area were blocked by storm debris for several days. Several homes suffered minor roof, shingle and siding damage. Several barns were destroyed.
- Flash Flood05/27/2018
Ellicott City, Howard County
1 death, $10.5M damage
What happened
Catastrophic flash flooding occurred in Ellicott City as a result of torrential short-term rainfall of 6-10 inches. One person died during a lull in the flooding when he attempted to help another person evacuate and was swept away. Floodwaters on the lower portion of Main Street in the 8000 block reached the bottom of second floors of businesses. In all, dozens of water rescues were performed, most from buildings.
- Heat08/06/2018
Southern Baltimore
2 deaths
What happened
Heat indices were around 100 degrees. The Maryland Department of Health reported 2 fatalities occurring during the week.
Hurricanes and tropical storms
Storms whose track crossed the state, newest first
- Hurricane Debby (2024)08/02/2024 · Landfall: FL, SC · 979 mbCategory 181 mph peak
- Tropical Storm Ophelia (2023)09/21/2023 · Landfall: NC · 981 mbTropical storm69 mph peak
- Hurricane Ida (2021)08/26/2021 · Landfall: LA · 929 mbCategory 4150 mph peak
- Hurricane Elsa (2021)07/01/2021 · Landfall: FL, NY, RI · 991 mbCategory 186 mph peak
- Hurricane Zeta (2020)10/24/2020 · Landfall: LA · 970 mbCategory 3115 mph peak
- Hurricane Isaias (2020)07/28/2020 · Landfall: NC · 986 mbCategory 192 mph peak
- Tropical Storm Andrea (2013)06/06/2013 · Landfall: FL · 992 mbTropical storm63 mph peak
- Hurricane Hanna (2008)08/28/2008 · Landfall: SC · 977 mbCategory 186 mph peak
- Hurricane Ernesto (2006)08/25/2006 · Landfall: FL, NC · 985 mbCategory 175 mph peak
- Hurricane Cindy (2005)07/04/2005 · Landfall: LA, MS · 991 mbCategory 175 mph peak
Flood insurance
National Flood Insurance Program policies and claims
33,232 homes in Maryland have flood insurance, about 1.7% of residential buildings. In high-risk flood zones, 16,675 of 22,558 homes (74%) are insured.
- Hurricane Isabel$174M · 6,269 claims
- Hurricane Sandy$21.28M · 1,615 claims
- Flooding$6.88M · 775 claims
- Hurricane Fran$5.79M · 738 claims
- Mid-spring storms$5.57M · 199 claims
- Hurricane Irene$3.16M · 314 claims
Drinking water
460 community water systems serve about 5,531,909 people
Since 2021, 136 systems reported 179 health-based violations. 24 systems had a violation of any kind still open at last report. These had the most:
- Town of North EastServes 8,600 · Surface water · Local government10 health violations+1 monitoring or reporting
- Town of PerryvilleServes 4,413 · Surface water · Local government5 health violations+52 monitoring or reporting
- Tebbston on MagothyServes 52 · Groundwater · Private5 health violations+6 monitoring or reporting
- City of Pocomoke CityServes 4,100 · Groundwater · Local government4 health violations+2 monitoring or reporting
- City of BaltimoreServes 1,600,000 · Surface water · Local government3 health violations+9 monitoring or reporting
- Town of St. MichaelsServes 2,650 · Groundwater · Local government3 health violations+2 monitoring or reporting
- Springfield Hospital DistributionServes 1,500 · Purchased surface water · State3 health violations+1 monitoring or reporting
- Town of FriendsvilleServes 622 · Surface water · Local government3 health violations
Select a county above to see every system that serves it.
Climate in the largest cities
1991-2020 normals from the nearest NOAA weather station
| City | July high | Jan low | Rain | Snow |
|---|---|---|---|---|
| Baltimore | 90°F | 30°F | 43.7 in | - |
| Columbia | 89°F | 26°F | 47.5 in | - |
| Germantown | 84°F | 25°F | 47.9 in | 31.4 in |
| Frederick | 89°F | 27°F | 43.5 in | - |
| Waldorf | 85°F | 25°F | 48.1 in | 15.1 in |
| Silver Spring | 87°F | 25°F | 44.0 in | 15.8 in |
| Ellicott City | 87°F | 27°F | - | - |
| Glen Burnie | 89°F | 25°F | 45.0 in | 19.3 in |
Pollution sites
26 Superfund sites and 162 toxic release facilities
Superfund sites
- 68th Street Dump/Industrial EnterprisesProposed NPL Site, Rosedale
- Aberdeen Proving Ground (Edgewood Area)Final NPL Site, Edgewood
- Aberdeen Proving Ground (Michaelsville Landfill)Final NPL Site, Aberdeen
- Andrews Air Force BaseFinal NPL Site, Andrews Air Force Base
- Bear Creek SedimentsFinal NPL Site, Sparrows Point
- Beltsville Agricultural Research Center (Usda)Final NPL Site, Beltsville
- Brandywine DrmoFinal NPL Site, Brandywine
- Bush Valley LandfillFinal NPL Site, Abingdon
Largest toxic releases
- Darling Ingredients Inc.- Linkwood Facility1.6 million lbs, Linkwood
- Perdue Agribusiness LLC - Salisbury MD268,238 lbs, Salisbury
- U.S. Navy Naval Support Facility Indian Head205,210 lbs, Indian Head
- Xerxes Corp114,060 lbs, Williamsport
- Aes Warrior Run Inc100,961 lbs, Cumberland
- Grace Davison-Curtis Bay Works100,349 lbs, Baltimore
- Brandon Shores & Wagner Complex97,303 lbs, Curtis Bay
- Terumo Medical Corp72,174 lbs, Elkton
Facilities in Maryland reported 3.0 million lbs of toxic releases in 2024, 653,399 lbs of it into the air.
Frequently asked questions
- What is the biggest natural hazard in Maryland?
- By expected annual loss, heat wave costs the most in Maryland ($140M a year), according to FEMA's National Risk Index.
- How many storms hit Maryland each year?
- NOAA recorded 24,003 storm events in Maryland since 1996, about 774 a year. The most common type is thunderstorm wind.
- How many homes in Maryland have flood insurance?
- 33,232 residential flood insurance policies are in force in Maryland. Since 1978 the National Flood Insurance Program has paid $340M on 20,800 claims here.
- How many Superfund sites are in Maryland?
- Maryland has 26 Superfund sites on or deleted from EPA's National Priorities List.
Source: FEMA, NOAA, EPA · Last updated 08/01/2026 · Storm counts include events in forecast zones that touch each county. This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.