Weather & Climate in Olney, MD
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Olney 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. Annual precipitation totals 41.3 inches. The area receives 15.8 inches of snow annually, a moderate snowfall amount. Air quality is rated Good with a median AQI of 40. 76% of days have good air quality. The city sits at an elevation of 509 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) |
Geography
| Elevation | 509 ft (155 m) |
| Area | 16.3 sq mi (42.1 km²) |
| Population Density | 2,225/sq mi |
| Coordinates | 39.1443°N, 77.0714°W |
| Timezone | America/New_York |
| County | Montgomery County County |
| Nearest Airport | Ronald Reagan Washington Ntl (DCA) 20 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 40.0 |
| Rating | Good |
| Good Days % | 76.1% |
| Unhealthy Days | 0 |
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
23 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M3.6.
| Jul 16, 2010 | 5 km NNW of Barnesville, Maryland | M3.6 | 32 km | 7 km |
| Jun 13, 2019 | 9 km N of Blain, Pennsylvania | M3.4 | 147 km | 27 km |
| Oct 23, 1990 | 3 km W of Hancocks Bridge, New Jersey | M3.2 | 141 km | 10 km |
| Jun 3, 2010 | 4 km ENE of Franklintown, Pennsylvania | M3.1 | 105 km | 2 km |
| Jan 17, 2016 | 3 km NE of Ranson, West Virginia | M3.0 | 68 km | 5 km |
| Oct 2, 2010 | 10 km NNW of Ashland, Virginia | M3.0 | 149 km | 19 km |
| Nov 14, 1997 | 0 km S of Rothsville, Pennsylvania | M3.0 | 132 km | 5 km |
| Apr 24, 2009 | 1 km S of Franklintown, Pennsylvania | M2.9 | 102 km | 1 km |
| Sep 15, 2019 | 5 km ESE of East Berlin, Pennsylvania | M2.8 | 88 km | 5 km |
| Jul 1, 2009 | 3 km ESE of Pennsville, New Jersey | M2.8 | 147 km | 5 km |
| Oct 25, 2009 | 4 km ENE of Franklintown, Pennsylvania | M2.8 | 106 km | 1 km |
| Mar 15, 1993 | 5 km W of Columbia, Maryland | M2.7 | 18 km | 5 km |
| Mar 11, 1995 | 0 km ENE of Landisville, Pennsylvania | M2.7 | 121 km | 5 km |
| Oct 28, 1994 | 1 km E of Mount Vernon, Maryland | M2.7 | 44 km | - |
| Oct 28, 1996 | 2 km W of Reinholds, Pennsylvania | M2.6 | 148 km | 5 km |
| Jan 18, 1994 | 3 km SE of Clay, Pennsylvania | M2.6 | 137 km | 5 km |
| Jun 25, 2021 | 2 km SE of Woodlawn, Maryland | M2.6 | 36 km | 3 km |
| Jan 13, 1990 | 6 km ENE of Eldersburg, Maryland | M2.6 | 35 km | 5 km |
| Aug 25, 2011 | 7 km SE of Mineral, Virginia | M2.6 | 149 km | 6 km |
| Sep 29, 1997 | Virginia | M2.5 | 49 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 | 214 km |
| 2003 | Isabel | Category 1 | 75 mph | 277 km |
| 1999 | Floyd | Category 1 | - | 274 km |
| 1986 | Charley | Category 1 | 81 mph | 254 km |
| 1985 | Gloria | Category 2 | 98 mph | 238 km |
Source: NOAA IBTrACS (Category 1+, 1980-2026).
Tornado History
487 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 9 fatalities, 381 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Apr 28, 2002 | EF4 | 67 km | 38.0 mi | 3 |
| Sep 17, 2004 | EF3 | 94 km | 9.0 mi | 0 |
| Sep 24, 2001 | EF3 | 25 km | 17.5 mi | 2 |
| Jul 19, 1996 | EF3 | 40 km | 2.2 mi | 0 |
| May 22, 1983 | EF3 | 64 km | 2.0 mi | 0 |
| Jun 7, 1980 | EF3 | 88 km | 1.5 mi | 0 |
| Sep 5, 1979 | EF3 | 41 km | 17.9 mi | 1 |
| Jan 26, 1978 | EF3 | 74 km | 0.7 mi | 1 |
| Apr 1, 1973 | EF3 | 44 km | 9.8 mi | 0 |
| Jun 9, 1961 | EF3 | 39 km | 0.1 mi | 0 |
| Apr 5, 1952 | EF3 | 73 km | 17.5 mi | 0 |
| Sep 1, 2021 | EF2 | 53 km | 11.4 mi | 0 |
| Nov 2, 2018 | EF2 | 24 km | 5.5 mi | 0 |
| Jul 23, 2017 | EF2 | 66 km | 2.4 mi | 0 |
| May 8, 2008 | EF2 | 96 km | 3.4 mi | 0 |
| Sep 18, 2004 | EF2 | 86 km | 2.0 mi | 0 |
| Sep 17, 2004 | EF2 | 77 km | 13.0 mi | 0 |
| Sep 17, 2004 | EF2 | 95 km | 5.0 mi | 0 |
| Sep 17, 2004 | EF2 | 85 km | 8.0 mi | 0 |
| Sep 17, 2004 | EF2 | 66 km | 4.0 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Wildfire History
1 wildfire (100+ acres) recorded within 100 km. Largest: NCO (816 acres, 1999).
| Year | Name | Acres Burned | Distance |
| 1999 | NCO | 816 | 71 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 35°F (1°C) | 3.1 in | Coldest |
| February | 37°F (3°C) | 2.6 in | Driest |
| March | 45°F (7°C) | 3.7 in | |
| April | 56°F (13°C) | 3.2 in | |
| May | 65°F (18°C) | 3.6 in | |
| June | 73°F (23°C) | 4.0 in | |
| July | 78°F (26°C) | 4.0 in | Warmest |
| August | 76°F (24°C) | 3.1 in | |
| September | 69°F (20°C) | 4.0 in | Wettest |
| October | 57°F (14°C) | 3.5 in | |
| November | 47°F (8°C) | 3.3 in | |
| December | 39°F (4°C) | 3.4 in |
Olney has a seasonal temperature swing of 44°F / from 35°F in January to 78°F in July. Total annual precipitation is 41.3 inches, with September being the wettest month (4.0") and February the driest (2.6").