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Weather & Climate in Potomac, MD
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Potomac enjoys a temperate climate with an average annual temperature of 56°F (13°C). Winters average 35°F in January while summers reach 78°F in July. The area gets 293 sunny days per year, well above the U.S. average of 205 / making it one of the sunnier locations in the country. Annual precipitation totals 41.3 inches. Air quality is rated Good with a median AQI of 41. The city sits at an elevation of 302 feet.
Temperature
35°F Jan (1°C)
78°F Jul (26°C)
| Annual Average | 56.2°F |
| 4% above US avg | |
| January Average | 35°F (1°C) |
| July Average | 78°F (26°C) |
| Sunny Days | 293 days/yr |
Geography
| Elevation | 302 ft (92 m) |
| Area | 25.2 sq mi (65.2 km²) |
| Population Density | 1,837/sq mi |
| Coordinates | 39.0133°N, 77.1936°W |
| Timezone | America/New_York |
| County | Montgomery County County |
| Nearest Airport | Ronald Reagan Washington Ntl (DCA) 14 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 41.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively Moderate |
| Risk Score | 91.7 / 100 |
| Social Vulnerability | 19.9 / 100 |
| Community Resilience | 63.6 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Hurricane | Relatively Moderate |
| Earthquake | Relatively Moderate |
| Wildfire | Very Low |
| Flood | Relatively High |
| Hail | Relatively High |
| Strong Wind | Relatively High |
| Heat Wave | Relatively High |
| Winter Weather | Very High |
| Lightning | Relatively High |
| Ice Storm | Relatively Moderate |
| Drought | Relatively Moderate |
| Cold Wave | Relatively Moderate |
| Landslide | Relatively Low |
| Coastal Flood | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
40 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M5.8.
| Aug 23, 2011 | 11 km SSW of Mineral, Virginia | M5.8 | 139 km | 6 km |
| Aug 25, 2011 | 8 km SW of Mineral, Virginia | M4.5 | 136 km | 7 km |
| Aug 24, 2011 | 11 km SSW of Mineral, Virginia | M4.2 | 139 km | 0 km |
| Jul 16, 2010 | 5 km NNW of Barnesville, Maryland | M3.6 | 33 km | 7 km |
| Sep 1, 2011 | 7 km SSW of Mineral, Virginia | M3.4 | 135 km | 3 km |
| Aug 24, 2011 | 16 km NNW of Goochland, Virginia | M3.4 | 148 km | 0 km |
| Jan 30, 2012 | 9 km SSE of Louisa, Virginia | M3.1 | 137 km | 3 km |
| Jun 3, 2010 | 4 km ENE of Franklintown, Pennsylvania | M3.1 | 121 km | 2 km |
| Jan 17, 2016 | 3 km NE of Ranson, West Virginia | M3.0 | 64 km | 5 km |
| Mar 26, 2012 | 13 km S of Louisa, Virginia | M3.0 | 141 km | 9 km |
| Oct 12, 2011 | 9 km S of Louisa, Virginia | M3.0 | 138 km | 4 km |
| Nov 14, 1997 | 0 km S of Rothsville, Pennsylvania | M3.0 | 150 km | 5 km |
| Oct 2, 2010 | 10 km NNW of Ashland, Virginia | M3.0 | 132 km | 19 km |
| Apr 24, 2009 | 1 km S of Franklintown, Pennsylvania | M2.9 | 118 km | 1 km |
| Sep 15, 2019 | 5 km ESE of East Berlin, Pennsylvania | M2.8 | 104 km | 5 km |
| Mar 15, 2015 | 6 km SW of Mineral, Virginia | M2.8 | 134 km | 5 km |
| Aug 23, 2011 | 9 km SSW of Mineral, Virginia | M2.8 | 137 km | 0 km |
| Jan 14, 2025 | 1 km NNE of Wyndham, Virginia | M2.8 | 150 km | 0 km |
| Oct 25, 2009 | 4 km ENE of Franklintown, Pennsylvania | M2.8 | 122 km | 1 km |
| Feb 19, 2012 | 12 km S of Louisa, Virginia | M2.7 | 140 km | 3 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Hurricane History
5 hurricanes (Category 1+) recorded within 500 km since 1980. Strongest on record: Category 2.
| Year | Name | Category | Max Wind | Closest |
| 2011 | Irene | Category 1 | 75 mph | 216 km |
| 2003 | Isabel | Category 1 | 75 mph | 261 km |
| 1999 | Floyd | Category 1 | - | 264 km |
| 1986 | Charley | Category 1 | 81 mph | 250 km |
| 1985 | Gloria | Category 2 | 98 mph | 244 km |
Source: NOAA IBTrACS (Category 1+, 1980-2026).
Tornado History
486 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 9 fatalities, 375 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Apr 28, 2002 | EF4 | 52 km | 38.0 mi | 3 |
| Sep 24, 2001 | EF4 | 84 km | 10.0 mi | 0 |
| Sep 17, 2004 | EF3 | 76 km | 9.0 mi | 0 |
| Sep 24, 2001 | EF3 | 21 km | 17.5 mi | 2 |
| Jul 19, 1996 | EF3 | 57 km | 2.2 mi | 0 |
| May 22, 1983 | EF3 | 77 km | 2.0 mi | 0 |
| Sep 5, 1979 | EF3 | 28 km | 17.9 mi | 1 |
| Jan 26, 1978 | EF3 | 58 km | 0.7 mi | 1 |
| Apr 1, 1973 | EF3 | 27 km | 9.8 mi | 0 |
| Jun 9, 1961 | EF3 | 54 km | 0.1 mi | 0 |
| Apr 5, 1952 | EF3 | 89 km | 17.5 mi | 0 |
| Sep 1, 2021 | EF2 | 55 km | 11.4 mi | 0 |
| Nov 2, 2018 | EF2 | 37 km | 5.5 mi | 0 |
| Jul 23, 2017 | EF2 | 73 km | 2.4 mi | 0 |
| May 8, 2008 | EF2 | 78 km | 3.4 mi | 0 |
| Sep 17, 2004 | EF2 | 60 km | 13.0 mi | 0 |
| Sep 17, 2004 | EF2 | 67 km | 8.0 mi | 0 |
| Sep 17, 2004 | EF2 | 82 km | 2.0 mi | 0 |
| Sep 17, 2004 | EF2 | 28 km | 15.0 mi | 0 |
| Sep 17, 2004 | EF2 | 48 km | 4.0 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Wildfire History
3 wildfires (100+ acres) recorded within 100 km. Largest: SMITH RUN FIRE (1,908 acres, 2011).
| Year | Name | Acres Burned | Distance |
| 2011 | SMITH RUN FIRE | 1,908 | 88 km |
| 1999 | NCO | 816 | 54 km |
| 1984 | UNNAMED | 696 | 98 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 35°F (1°C) | 2.9 in | Coldest |
| February | 35°F (2°C) | 2.7 in | Driest |
| March | 44°F (7°C) | 3.5 in | |
| April | 54°F (12°C) | 3.2 in | |
| May | 63°F (17°C) | 4.1 in | Wettest |
| June | 72°F (22°C) | 3.7 in | |
| July | 78°F (26°C) | 3.8 in | Warmest |
| August | 75°F (24°C) | 3.7 in | |
| September | 68°F (20°C) | 3.6 in | |
| October | 56°F (14°C) | 3.2 in | |
| November | 47°F (8°C) | 3.4 in | |
| December | 37°F (3°C) | 3.1 in |
Potomac has a seasonal temperature swing of 44°F / from 35°F in January to 78°F in July. Total annual precipitation is 40.9 inches, with May being the wettest month (4.1") and February the driest (2.7").