Hurricanes and Tornadoes That Hit Herndon, VA

The nearest NOAA station with 1991–2020 climate normals is Washington Dc Dulles Airport, VA, 4 miles west of Herndon at 290 feet. July is the warmest, with an average high of 88°F and low of 67°F; January is the coolest, at 43°F and 25°F. May is the wettest at 4.7 inches of precipitation on average and February the driest at 2.6 inches; the year adds up to 43.2 inches over 74 days with at least a tenth of an inch. June to November, the hurricane season months, bring 53% of the year's precipitation (22.7 of 43.2 inches); the other six months are drier. October has brought the most of the 26 tropical systems that passed within 75 miles (9); a normal October there has highs of 68°F and 3.7 inches of precipitation. Highs reach 90°F on about 33 days a year, almost all from May to September. Lows fall below freezing on about 102 nights a year. Snowfall averages 21.0 inches a year, most of it in February. That 43.2 inches is more than at 22 of the 109 Virginia stations used on this site (20%). Reston, 3 miles east, has its own station (Vienna, VA): 43.5 inches a year, 0.3 more than here, and a July average high of 84°F against 88°F.

Water temperature at the NOAA tide station Washington, DC, 21 miles east, averaged 84°F in July and 39°F in January over 2021–2025. It averaged 80°F or warmer from July to August. Sea level at the Washington tide gauge, 21 miles from Herndon, has risen 1.40 ± 0.05 inches per decade from 1924 to 2025, NOAA's linear trend; at that pace it is 14.0 inches in a hundred years. That is faster than at 84 of the 144 U.S. gauges with a NOAA trend.

Since 1996, the National Weather Service has logged 757 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Herndon: 473 thunderstorm wind reports, 161 floods, 120 flash floods, 2 lightning strikes and 1 heavy rain event. They killed 3 people and injured 0, and the NWS estimated $3.9 million in property and crop damage. The strongest thunderstorm gust on record here was 81 mph, on May 23, 2019. July has had the most flash floods, 54 of 120. Of the 364 Virginia cities on this site with a flash flood on record, 344 have had fewer than Herndon.

Flood insurance policyholders in Herndon's 2 ZIP codes have filed 48 claims with the National Flood Insurance Program since 1979, and were paid $79,000 for buildings and contents, in the dollars of each year. The year with the most claims was 2011, with 15. 17% of the claims carry the name of a storm or flood event; the rest have no event name. Of the 183 Virginia cities on this site with 10 or more claims, 94 have fewer than Herndon.