Live
Active alerts for this county
Severe Thunderstorm Watch
District of Columbia, DC; Allegany, MD; Anne Arundel, MD; Baltimore, MD; Calvert, MD; Carroll, MD; Cecil, MD; Charles, MD; Frederick, MD; Harford, MD; Howard, MD; Montgomery, MD; Prince Georges, MD; St. Marys, MD; Washington, MD; Baltimore City, MD; Arlington, VA; Clarke, VA; Culpeper, VA; Fairfax, VA; Fauquier, VA; Frederick, VA; Greene, VA; King George, VA; Loudoun, VA; Madison, VA; Orange, VA; Page, VA; Prince William, VA; Rappahannock, VA; Shenandoah, VA; Spotsylvania, VA; Stafford, VA; Warren, VA; City of Alexandria, VA; City of Fairfax, VA; City of Falls Church, VA; City of Fredericksburg, VA; City of Manassas, VA; City of Manassas Park, VA; City of Winchester, VA; Berkeley, WV; Hampshire, WV; Hardy, WV; Jefferson, WV; Mineral, WV; Morgan, WV
St. Mary's County, Maryland severe weather history spans 648 recorded events between 1962 and 2026. The dominant hazard is thunderstorm wind, accounting for 51.9% of all recorded events. It ranks #479 nationally and #10 in Maryland.
648
Recorded events
0
Direct deaths
14
Direct injuries
$13.5M
Property damage
The record
What the St. Mary's County, Maryland severe weather history record shows
Across the archive, St. Mary's County, Maryland severe weather history averages 10.1 recorded events a year. The busiest stretch on record is the 2010s, with 222 events logged in that decade alone. Roughly 35 events fall before 1990 and 613 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The costliest is thunderstorm wind, with $7.3M in reported property damage. In total, 9 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in St. Mary's County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Thunderstorm Wind | 336 | 0 | $7.3M | 89 | 1963–2026 |
| Flood | 85 | 0 | $30K | 0 | 2006–2023 |
| Hail | 80 | 0 | $12K | 2.75 | 1962–2025 |
| Flash Flood | 72 | 0 | $755K | 0 | 1996–2022 |
| Tornado | 34 | 0 | $4.6M | F2 | 1967–2025 |
| Heavy Rain | 22 | 0 | $0 | 0 | 2000–2006 |
| Lightning | 16 | 0 | $662K | 0 | 1996–2008 |
| Storm Surge/Tide | 2 | 0 | $100K | 0 | 1996–1999 |
| Dust Devil | 1 | 0 | $1K | 0 | 2009–2009 |
Decade by decade
St. Mary's County, Maryland severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
34 mapped tornado paths intersect this county: 32 touched down inside it and 2 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 2002-04-28 | EF4 | 3 | 122 | 38.0 mi | Crossed in |
| 1994-07-27 | EF2 | 0 | 0 | 0.8 mi | Touched down here |
| 1983-10-13 | EF2 | 0 | 0 | 4.0 mi | Touched down here |
| 2025-07-01 | EF1 | 0 | 0 | 1.0 mi | Touched down here |
| 2022-05-27 | EF1 | 0 | 0 | 4.1 mi | Touched down here |
| 2015-06-27 | EF1 | 0 | 0 | 16.1 mi | Crossed in |
| 2011-04-28 | EF1 | 0 | 0 | 3.4 mi | Touched down here |
| 2004-07-14 | EF1 | 0 | 0 | 3.0 mi | Touched down here |
| 1996-07-12 | EF1 | 0 | 0 | 1.2 mi | Touched down here |
| 1984-05-08 | EF1 | 0 | 3 | 3.0 mi | Touched down here |
Significant events
Deadliest events on record in St. Mary's County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Aug 17, 1994 | Thunderstorm Wind | Compton | 0 | 5 | $0 |
| Jul 3, 1987 | Thunderstorm Wind | 0 | 3 | $0 | |
| May 8, 1984 | Tornado | 0 | 3 | $2.5M | |
| Jul 19, 2009 | Dust Devil | VALLEY LEE | 0 | 1 | $1K |
| May 22, 2001 | Thunderstorm Wind | CLEMENTS | 0 | 1 | $40K |
| May 8, 1984 | Tornado | 0 | 1 | $250K |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Hundreds of trees blew down around Charlotte Hall, Golden Beach, and Mechanicsville. Many trees blew down onto houses and cars. Numerous trees blew down along Golden Beach Road and on northbound MD-5 Leonardtown Road near Charlotte Hall and Golden Beach. Numerous trees blew down on MD-6 New Market Turner Road between Four Seasons Court and Flora Corner Road. Large trees blew down near the intersection of MD-6 New Market Turner Road and Lockes Hill Road. Dozens of trees blew down around Mechanicsville, with one trapping a sherriff.
A waterspout came onshore from the Chesapeake Bay near Chaptico as a tornado, and caused structural damage to several properties in addition to extensive tree damage. The storm destroyed six barns and a carport at two farms along Hurry Road, and also destroyed a barn off Beavan Lane. Several homes and commercial buildings were also damaged. Since an official damage survey was not conducted, the path length, width and F scale rating were estimated based on reports from Emergency Management and newspapers.
St. Mary's County Emergency Management reported 2 homes damaged along Mount Chance Farm Lane in Clements. One home sustained shingle damage and broken windows. A tree also fell onto a vehicle. A second home sustained chimney damage. Extensive damage was reported to a 50' by 72' tobacco barn. The roof collapsed on top of the farm truck and combine as well as numerous other pieces of farm equipment. Also, several large cedar trees were downed on the property. A nearby automated observation at St. Inigoes measured a wind gust of 50 knots.
Context
Risk, population and federal disasters
Very Low
FEMA NRI risk rating
115,126
Population (ACS)
$408K
Median home value
18
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Jan 24, 2026 | Winter Storm | SEVERE WINTER STORM | EM |
| Feb 4, 2021 | Hurricane | TROPICAL STORM ISAIAS | DR |
| Mar 26, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
| Nov 20, 2012 | Hurricane | HURRICANE SANDY | DR |
| Oct 28, 2012 | Hurricane | HURRICANE SANDY | EM |
Within the county
Most affected places
- Great Mills 147
Quick answers
Frequently asked
How many severe weather events have been recorded in St. Mary's County, Maryland?
648 events are on record between 1962 and 2026, causing 0 direct deaths and $13.5M in property damage.
What is the most common severe weather hazard in St. Mary's County?
Thunderstorm Wind, with 336 recorded events — 51.9% of everything in the archive for this county.
How many tornadoes have crossed St. Mary's County?
34 mapped tornado paths intersect the county boundary; 32 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover St. Mary's County?
18 federal disaster declarations from FEMA include St. Mary's County, each tied to a specific incident period.
How risky is St. Mary's County compared with the rest of the country?
FEMA's National Risk Index rates St. Mary's County as very low risk, placing it in the 43 percentile of its state for expected annual loss.
Where does the St. Mary's County, Maryland severe weather history data come from?
Every figure is drawn from United States federal public-domain records: NOAA/NCEI Storm Events for the event archive, NOAA SPC SVRGIS for mapped tornado paths, FEMA for disaster declarations and risk ratings, and the U.S. Census for population context. Dates are shown in UTC and recent entries may still be revised by NOAA.
Nearby
Neighbouring counties
- Queen Anne's County 386
- Somerset County 168
- Prince George's County 960
- Talbot County 327
- Montgomery County 1,599
- Washington County 652
Cite this page
“St. Mary’s County, Maryland.” Severe Weather History. severeweatherhistory.com/county/maryland/st-marys-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.