All-time weather records — Herndon, VA
Climate change signal in Herndon
of Herndon's all-time daily heat records were set in the last decade (78 of 366 records since 2015).
of all-time daily cold records were set in the last decade (13 of 366 records since 2015).
If records were spread evenly across the station's history, you'd expect roughly 5% per decade. Decade-by-decade, here's where each record-breaking day was set:
| Decade | Heat records set | # | Cold records set | # |
|---|---|---|---|---|
| 1960s | 43 | 83 | ||
| 1970s | 43 | 110 | ||
| 1980s | 52 | 97 | ||
| 1990s | 77 | 40 | ||
| 2000s | 44 | 15 | ||
| 2010s | 57 | 20 | ||
| 2020s | 50 | 1 |
Records are the all-time daily extremes that are still standing — each daily record can only be held by one year. The station's earliest hot record was set in 1960, the latest in 2026. Period of observation: 1960-2026.
Records by month
| Month | Hottest day | Coldest day | Wettest day |
|---|---|---|---|
| January | 79.0°F — Jan 26, 2024 | -18.0°F — Jan 22, 1984 | 2.00 in — Jan 30, 2013 |
| February | 80.1°F — Feb 21, 2018 | -14.1°F — Feb 18, 1979 | 2.33 in — Feb 16, 2003 |
| March | 89.1°F — Mar 12, 1990 | -0.9°F — Mar 15, 1993 | 2.69 in — Mar 21, 2019 |
| April | 93.0°F — Apr 6, 2010 | 17.1°F — Apr 1, 1969 | 3.99 in — Apr 30, 2014 |
| May | 97.0°F — May 29, 1969 | 28.0°F — May 7, 1970 | 3.73 in — May 11, 2008 |
| June | 102.0°F — Jun 29, 2012 | 36.0°F — Jun 8, 1977 | 10.67 in — Jun 21, 1972 |
| July | 105.1°F — Jul 22, 2011 | 41.0°F — Jul 1, 1988 | 5.02 in — Jul 21, 2018 |
| August | 104.0°F — Aug 20, 1983 | 37.9°F — Aug 29, 1982 | 4.68 in — Aug 11, 1984 |
| September | 100.0°F — Sep 6, 2023 | 30.0°F — Sep 24, 1974 | 5.52 in — Sep 14, 1966 |
| October | 96.1°F — Oct 2, 2019 | 15.1°F — Oct 24, 1969 | 4.26 in — Oct 29, 2012 |
| November | 84.0°F — Nov 1, 1982 | 9.0°F — Nov 24, 1989 | 2.59 in — Nov 27, 1993 |
| December | 79.0°F — Dec 6, 1998 | -4.0°F — Dec 25, 1989 | 2.92 in — Dec 18, 1977 |
Click a month to see every daily record for that month in Herndon.