Herndon, VA
Climate overview — based on NOAA 1991-2020 normals from WASHINGTON DC DULLES AP, VA US.
Year-round temperatures (°F)
Climate summary
Herndon has an annual average temperature of 55.7°F with about 43.2 inches of precipitation per year and 21 inches of snow. The warmest month is July (average high 87.6°F), and the coldest is January (average low 25.2°F). May is typically the wettest month (4.72 in) and February the driest (2.61 in). Snow typically falls from November through March.
Best time to visit Herndon
Full guide →Climate change signal
All-time records →78 of 366 (21.3%) of Herndon's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.
| 1960s | 43 | |
| 1970s | 43 | |
| 1980s | 52 | |
| 1990s | 77 | |
| 2000s | 44 | |
| 2010s | 57 | |
| 2020s | 50 |
Bars: number of all-time daily heat records still standing that were set in each decade.
Monthly averages
| Month | Avg High | Avg Low | Avg Temp | Precipitation | Snow | Rainy days |
|---|---|---|---|---|---|---|
| January | 42.6°F | 25.2°F | 33.9°F | 2.94 in | 6.9 in | 10 |
| February | 46.1°F | 26.7°F | 36.4°F | 2.61 in | 7.0 in | 9 |
| March | 54.8°F | 33.6°F | 44.2°F | 3.50 in | 3.9 in | 11 |
| April | 66.8°F | 43.2°F | 55.0°F | 3.47 in | 0.1 in | 11 |
| May | 75.0°F | 53.0°F | 64.0°F | 4.72 in | — | 13 |
| June | 83.1°F | 61.9°F | 72.5°F | 4.30 in | — | 11 |
| July | 87.6°F | 66.8°F | 77.2°F | 4.15 in | — | 11 |
| August | 86.3°F | 65.2°F | 75.7°F | 3.53 in | — | 9 |
| September | 79.3°F | 57.9°F | 68.6°F | 3.94 in | — | 9 |
| October | 67.8°F | 45.3°F | 56.6°F | 3.65 in | — | 8 |
| November | 56.5°F | 35.6°F | 46.0°F | 3.13 in | 0.3 in | 9 |
| December | 46.5°F | 29.0°F | 37.7°F | 3.30 in | 2.8 in | 10 |
Climate twins of Herndon
Why these? →The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).