One Loudoun weather by month
What a typical year looks like in One Loudoun, Virginia: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Washington Dulles International Airport, 13 km from One Loudoun; records cover 1960–2026.
The year at a glance
- Precipitation a year
- 43.2 in1098 mm
- Snow a year
- 21 in53 cm
- Last spring freeze
- Apr 15
- First fall freeze
- Oct 18
- Heating degree days
- 4,605
- Cooling degree days
- 1,231
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 9°−13° (heating, 99%) and 96°36° (cooling, 1%).
Month by month
One Loudoun in January
Highs average 43°6° and lows 25°−4°, with 2.9 in75 mm of precipitation and 7 in18 cm of snow in a typical January.
- Record high
- 79°26° (2024)
- Record low
- −18°−28° (1984)
- Heating degree days
- 964
- Cooling degree days
- 0
One Loudoun in February
Highs average 46°8° and lows 27°−3°, with 2.6 in66 mm of precipitation and 7 in18 cm of snow in a typical February.
- Record high
- 80°27° (2018)
- Record low
- −14°−26° (1979)
- Heating degree days
- 801
- Cooling degree days
- 0
One Loudoun in March
Highs average 55°13° and lows 34°1°, with 3.5 in89 mm of precipitation and 4 in10 cm of snow in a typical March.
- Record high
- 89°32° (1990)
- Record low
- −1°−18° (1993)
- Heating degree days
- 647
- Cooling degree days
- 2
One Loudoun in April
Highs average 67°19° and lows 43°6°, with 3.5 in88 mm of precipitation and 0.1 in0.3 cm of snow in a typical April.
- Record high
- 93°34° (1960)
- Record low
- 17°−8° (1969)
- Heating degree days
- 320
- Cooling degree days
- 20
One Loudoun in May
Highs average 75°24° and lows 53°12°, with 4.7 in120 mm of precipitation in a typical May.
- Record high
- 97°36° (1969)
- Record low
- 28°−2° (1970)
- Heating degree days
- 115
- Cooling degree days
- 84
One Loudoun in June
Highs average 83°28° and lows 62°17°, with 4.3 in109 mm of precipitation in a typical June.
- Record high
- 102°39° (2012)
- Record low
- 36°2° (1977)
- Heating degree days
- 13
- Cooling degree days
- 238
One Loudoun in July
Highs average 88°31° and lows 67°19°, with 4.2 in105 mm of precipitation in a typical July.
- Record high
- 105°41° (2011)
- Record low
- 41°5° (1988)
- Heating degree days
- 0
- Cooling degree days
- 378
One Loudoun in August
Highs average 86°30° and lows 65°18°, with 3.5 in90 mm of precipitation in a typical August.
- Record high
- 104°40° (1983)
- Record low
- 38°3° (1982)
- Heating degree days
- 1
- Cooling degree days
- 334
One Loudoun in September
Highs average 79°26° and lows 58°14°, with 3.9 in100 mm of precipitation in a typical September.
- Record high
- 100°38° (2023)
- Record low
- 30°−1° (1974)
- Heating degree days
- 45
- Cooling degree days
- 152
One Loudoun in OctoberThis month
Highs average 68°20° and lows 45°7°, with 3.7 in93 mm of precipitation in a typical October.
- Record high
- 96°36° (2019)
- Record low
- 15°−9° (1969)
- Heating degree days
- 284
- Cooling degree days
- 22
One Loudoun in November
Highs average 57°14° and lows 36°2°, with 3.1 in80 mm of precipitation and 0.3 in0.8 cm of snow in a typical November.
- Record high
- 84°29° (1971)
- Record low
- 9°−13° (1989)
- Heating degree days
- 570
- Cooling degree days
- 1
One Loudoun in December
Highs average 47°8° and lows 29°−2°, with 3.3 in84 mm of precipitation and 2.8 in7.1 cm of snow in a typical December.
- Record high
- 79°26° (1998)
- Record low
- −4°−20° (1989)
- Heating degree days
- 845
- Cooling degree days
- 0