Herndon, VA Weather & Climate Normals
What a normal year in Herndon actually looks like
On the 30-year record NOAA keeps for Herndon, VA, the comfort score comes out to 48/100, strongly seasonal: Comfortable weather is limited to a shorter window; summers, winters, or precipitation swing wide. Only 5 months a year land in the 55–75°F range this site treats as mild.
How much Herndon's weather actually swings
Average temperatures in Herndon run from 34°F in Jan up to 77°F in Jul, a 43.3°F seasonal swing, a middling gap by national standards.
Herndon, month by month
| Month | Avg high | Avg low | Precip | Snow |
|---|---|---|---|---|
| Jan | 43°F | 25°F | 2.94in | 6.9in |
| Feb | 46°F | 27°F | 2.61in | 7in |
| Mar | 55°F | 34°F | 3.5in | 3.9in |
| Apr | 67°F | 43°F | 3.47in | 0.1in |
| May | 75°F | 53°F | 4.72in | 0in |
| Jun | 83°F | 62°F | 4.3in | 0in |
| Jul | 88°F | 67°F | 4.15in | 0in |
| Aug | 86°F | 65°F | 3.53in | 0in |
| Sep | 79°F | 58°F | 3.94in | 0in |
| Oct | 68°F | 45°F | 3.65in | 0in |
| Nov | 57°F | 36°F | 3.13in | 0.3in |
| Dec | 47°F | 29°F | 3.3in | 2.8in |
If you're timing a visit, Apr, May, Jun, Sep, and Oct are Herndon's mildest stretch; if you're moving there, you should plan around Jul's heat and Jan's cold instead.
How wet Herndon actually gets
Over a typical year, Herndon sees about 43.24in of precipitation a year across roughly 121 days with measurable rain or snow, with 21in of snow a year.
Herndon against the rest of the country
Out of 4876 cities scored here, Herndon comes in at 2350; within VA alone it ranks 52 of 63. Population is about 25,180.
Checking the actual forecast
These figures come from Washington Dc Dulles Ap, VA US, the NOAA station 4.6 miles from Herndon, averaged over 30 years, not tomorrow's forecast.
More on how this is worked out
Why this uses the nearest NOAA station · How the comfort score is calculated