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Weather & Climate in Bel Air South, MD

Temperature, precipitation, air quality, natural hazards, and monthly weather data.

Bel Air South experiences four distinct seasons with an average annual temperature of 55°F (13°C). Winters average 33°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 48.3 inches (wetter than the 38-inch national average). Air quality is rated Good with a median AQI of 41. The city sits at an elevation of 220 feet.

Temperature

33°F Jan (0°C) 78°F Jul (26°C)
Annual Average55.4°F
3% above US avg
January Average33°F (0°C)
July Average78°F (26°C)
Sunny Days293 days/yr

Geography

Elevation220 ft (67 m)
Area15.7 sq mi (40.8 km²)
Population Density2,713/sq mi
Coordinates39.5081°N, 76.3094°W
TimezoneAmerica/New_York
CountyHarford County County
Nearest AirportBaltimore/Washington International Thurgood Marshall (BWI)
30 miles away

Precipitation & Snow

Annual Rainfall 48.3"
27% above US avg
Wettest Month (May) 4.25"
Driest Month (Feb) 2.83"

Air Quality

AQI Median41.0
RatingGood

Natural Hazard Risk

Overall RiskRelatively Low
Risk Score72.5 / 100
Social Vulnerability10.6 / 100
Community Resilience91.6 / 100

Hazard Breakdown

Tornado Relatively Low
Hurricane Relatively Moderate
Earthquake Relatively Low
Wildfire Very Low
Flood Relatively Moderate
Hail Very Low
Strong Wind Relatively Moderate
Heat Wave Relatively Moderate
Winter Weather Relatively High
Lightning Relatively Moderate
Ice Storm Relatively Low
Drought Relatively Moderate
Cold Wave Relatively Moderate
Landslide Very Low
Coastal Flood Relatively Low
Avalanche Very Low
Source: FEMA National Risk Index v1.20 (Dec 2025)

Earthquake History

28 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.6.

Jan 16, 1994 2 km W of Sinking Spring, Pennsylvania M4.6 94 km 5 km
Jan 16, 1994 0 km E of Sinking Spring, Pennsylvania M4.2 95 km 5 km
Jul 16, 2010 5 km NNW of Barnesville, Maryland M3.6 99 km 7 km
Jun 13, 2019 9 km N of Blain, Pennsylvania M3.4 144 km 27 km
Oct 23, 1990 3 km W of Hancocks Bridge, New Jersey M3.2 69 km 10 km
Jun 3, 2010 4 km ENE of Franklintown, Pennsylvania M3.1 86 km 2 km
Jan 17, 2016 3 km NE of Ranson, West Virginia M3.0 132 km 5 km
Nov 14, 1997 0 km S of Rothsville, Pennsylvania M3.0 71 km 5 km
Apr 24, 2009 1 km S of Franklintown, Pennsylvania M2.9 87 km 1 km
Jan 16, 1994 0 km SSE of Sinking Spring, Pennsylvania M2.9 94 km 5 km
Sep 15, 2019 5 km ESE of East Berlin, Pennsylvania M2.8 69 km 5 km
May 10, 1993 1 km NW of Whitfield, Pennsylvania M2.8 97 km 5 km
Jul 1, 2009 3 km ESE of Pennsville, New Jersey M2.8 73 km 5 km
Oct 25, 2009 4 km ENE of Franklintown, Pennsylvania M2.8 87 km 1 km
Mar 11, 1995 0 km ENE of Landisville, Pennsylvania M2.7 66 km 5 km
Oct 28, 1994 1 km E of Mount Vernon, Maryland M2.7 34 km
Mar 15, 1993 5 km W of Columbia, Maryland M2.7 59 km 5 km
Jan 25, 2015 4 km ESE of Downingtown, Pennsylvania M2.6 78 km 2 km
Jun 25, 2021 2 km SE of Woodlawn, Maryland M2.6 41 km 3 km
Jan 13, 1990 6 km ENE of Eldersburg, Maryland M2.6 50 km 5 km
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.

Hurricane History

4 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 193 km
1991 Bob Category 3 109 mph 293 km
1986 Charley Category 1 75 mph 254 km
1985 Gloria Category 2 98 mph 199 km
Source: NOAA IBTrACS (Category 1+, 1980–2026).

Tornado History

455 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF3. Total: 10 fatalities, 342 injuries.

Date Rating Distance Path Fatalities
Sep 1, 2021 EF3 93 km 12.4 mi 0
Jul 14, 2004 EF3 89 km 7.5 mi 0
Sep 24, 2001 EF3 86 km 17.5 mi 2
Jul 19, 1996 EF3 58 km 2.2 mi 0
Jul 27, 1994 EF3 52 km 4.0 mi 0
May 22, 1983 EF3 83 km 2.0 mi 0
Jun 7, 1980 EF3 77 km 1.5 mi 0
Jun 18, 1970 EF3 99 km 1.9 mi 1
Jun 9, 1961 EF3 43 km 0.1 mi 0
Apr 28, 1961 EF3 66 km 0.3 mi 0
Mar 22, 1955 EF3 78 km 9.6 mi 1
Apr 5, 1952 EF3 66 km 17.5 mi 0
Nov 4, 1950 EF3 79 km 15.9 mi 0
Sep 1, 2021 EF2 41 km 5.9 mi 0
Sep 1, 2021 EF2 77 km 11.4 mi 0
Aug 4, 2020 EF2 83 km 35.8 mi 0
Oct 31, 2019 EF2 81 km 0.5 mi 0
May 28, 2019 EF2 80 km 3.1 mi 0
Nov 2, 2018 EF2 76 km 5.5 mi 0
Jul 23, 2017 EF2 61 km 2.4 mi 0
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).

Tsunami History

1 tsunami recorded within 500 km.

Year Location Cause Max Wave Deaths Distance
1840 PHILADELPHIA, PENNSYLVANIA Earthquake 100 km
Source: NOAA/NCEI Historical Tsunami Database.

Wildfire History

4 wildfires (100+ acres) recorded within 100 km. Largest: KENTIS WEST (1,273 acres, 1991).

Year Name Acres Burned Distance
1991 KENTIS WEST 1,273 82 km
1988 BOMBAY ISLAND 1,020 81 km
2012 HOPEWELL FIRE 812 92 km
1985 BOMBAY HOOK 669 82 km
Source: NIFC/IRWIN Wildfire Records (100+ acres).

Monthly Weather

Month Avg Temperature Precipitation Summary
January 33°F (0°C) 3.2 in Coldest
February 33°F (1°C) 2.8 in Driest
March 42°F (5°C) 3.5 in
April 52°F (11°C) 3.7 in
May 62°F (16°C) 4.3 in Wettest
June 70°F (21°C) 4.2 in
July 78°F (26°C) 4.3 in Warmest
August 74°F (23°C) 4.2 in
September 67°F (19°C) 3.9 in
October 56°F (13°C) 3.2 in
November 46°F (8°C) 3.7 in
December 37°F (3°C) 3.7 in

Bel Air South has a seasonal temperature swing of 46°F / from 33°F in January to 78°F in July. Total annual precipitation is 44.5 inches, with May being the wettest month (4.3") and February the driest (2.8").

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