Home › Cities › United States › Virginia › Ashburn
Ashburn, Virginia climate
Cfa Humid subtropical
Ashburn has a seasonal mild-temperate climate (Humid subtropical, Köppen Cfa). The hottest month is July with an average daily high near 88°F, while the coldest is January averaging around 25°F at night. Precipitation is fairly even year-round, totalling about 43 inches. Light snow accumulates each winter (21 inches of snow per year on average).
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation split into rain and snow · 1991–2020 normals · hover a month for the exact figuresClear vs cloudy days
Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day countsAshburn climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 43 | 46 | 55 | 67 | 75 | 83 | 88 | 86 | 79 | 68 | 57 | 47 |
| Avg temp (°F) | 34 | 36 | 44 | 55 | 64 | 73 | 77 | 76 | 69 | 57 | 46 | 38 |
| Avg low (°F) | 25 | 27 | 34 | 43 | 53 | 62 | 67 | 65 | 58 | 45 | 36 | 29 |
| Precipitation (in) | 2.9 | 2.6 | 3.5 | 3.5 | 4.7 | 4.3 | 4.2 | 3.5 | 3.9 | 3.7 | 3.1 | 3.3 |
| Snowfall (in) | 6.9 | 7.0 | 3.9 | 0.1 | — | — | — | — | — | — | 0.3 | 2.8 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°F) | 43 | 46 | 55 | 67 | 75 | 83 |
| Avg temp (°F) | 34 | 36 | 44 | 55 | 64 | 73 |
| Avg low (°F) | 25 | 27 | 34 | 43 | 53 | 62 |
| Precipitation (in) | 2.9 | 2.6 | 3.5 | 3.5 | 4.7 | 4.3 |
| Snowfall (in) | 6.9 | 7.0 | 3.9 | 0.1 | — | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°F) | 88 | 86 | 79 | 68 | 57 | 47 |
| Avg temp (°F) | 77 | 76 | 69 | 57 | 46 | 38 |
| Avg low (°F) | 67 | 65 | 58 | 45 | 36 | 29 |
| Precipitation (in) | 4.2 | 3.5 | 3.9 | 3.7 | 3.1 | 3.3 |
| Snowfall (in) | — | — | — | — | 0.3 | 2.8 |
How often — frequency of weather events
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 10 | 9 | 11 | 11 | 13 | 11 | 11 | 9 | 9 | 8 | 9 | 10 |
| Days with high ≥ 90°F (days) | — | — | — | 0.4 | 1 | 6 | 13 | 9 | 3 | 0.2 | — | — |
| Days with low ≤ 32°F (days) | 24 | 21 | 15 | 4 | 0.2 | — | — | — | — | 2 | 13 | 22 |
| Days with snowfall ≥ 1 in (days) | 2 | 2 | 1 | 0.0 | — | — | — | — | — | — | 0.1 | 0.9 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 10 | 9 | 11 | 11 | 13 | 11 |
| Days with high ≥ 90°F (days) | — | — | — | 0.4 | 1 | 6 |
| Days with low ≤ 32°F (days) | 24 | 21 | 15 | 4 | 0.2 | — |
| Days with snowfall ≥ 1 in (days) | 2 | 2 | 1 | 0.0 | — | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 11 | 9 | 9 | 8 | 9 | 10 |
| Days with high ≥ 90°F (days) | 13 | 9 | 3 | 0.2 | — | — |
| Days with low ≤ 32°F (days) | — | — | — | 2 | 13 | 22 |
| Days with snowfall ≥ 1 in (days) | — | — | — | — | 0.1 | 0.9 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 62 | 62 | 62 | 62 | 62 | 59 | 57 | 55 | 54 | 52 | 58 | 61 |
| Clear days (≤ 30% cloud) | 6 | 5 | 6 | 6 | 6 | 6 | 7 | 8 | 9 | 10 | 7 | 6 |
| Partly cloudy days (30–70%) | 11 | 10 | 10 | 9 | 11 | 12 | 13 | 12 | 10 | 10 | 10 | 11 |
| Cloudy days (≥ 70%) | 14 | 13 | 15 | 14 | 15 | 12 | 12 | 11 | 11 | 11 | 13 | 14 |
| Relative humidity (%) | 83 | 82 | 79 | 77 | 77 | 73 | 67 | 67 | 70 | 75 | 78 | 83 |
| Wind speed (mph) | 5.2 | 5.4 | 5.5 | 5.0 | 4.1 | 3.6 | 3.3 | 3.3 | 3.7 | 4.0 | 4.3 | 4.5 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 62 | 62 | 62 | 62 | 62 | 59 |
| Clear days (≤ 30% cloud) | 6 | 5 | 6 | 6 | 6 | 6 |
| Partly cloudy days (30–70%) | 11 | 10 | 10 | 9 | 11 | 12 |
| Cloudy days (≥ 70%) | 14 | 13 | 15 | 14 | 15 | 12 |
| Relative humidity (%) | 83 | 82 | 79 | 77 | 77 | 73 |
| Wind speed (mph) | 5.2 | 5.4 | 5.5 | 5.0 | 4.1 | 3.6 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 57 | 55 | 54 | 52 | 58 | 61 |
| Clear days (≤ 30% cloud) | 7 | 8 | 9 | 10 | 7 | 6 |
| Partly cloudy days (30–70%) | 13 | 12 | 10 | 10 | 10 | 11 |
| Cloudy days (≥ 70%) | 12 | 11 | 11 | 11 | 13 | 14 |
| Relative humidity (%) | 67 | 67 | 70 | 75 | 78 | 83 |
| Wind speed (mph) | 3.3 | 3.3 | 3.7 | 4.0 | 4.3 | 4.5 |
Methodology & sources
Temperature & precipitation — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Washington Dulles Intl AP (NOAA GHCN station USW00093738), about 13 km from the city centre.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.