Mosquito season in Frederick County, VA: when it starts and ends
Mosquito months in Frederick County
In a normal year mosquito season in Frederick County, VA starts around April 7 and ends around October 29, about 29 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Frederick County, and when
- Start tipping out standing water weekly by March 24.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after October 29.
- 1 West Nile case since 2016 (last 2018): you should use repellent at dusk June to August, more so if over 60.
Frederick County against the rest of VA
Frederick County has the 99th longest season of 133 VA counties, at 205 days against 257 in Norfolk city and 172 in Highland County. Its mean temperature is 53.5°F.
- Buena Vista city: April 9 to November 1 (206 days, 0 WNV)
- Lexington city: April 9 to November 1 (206 days, 0 WNV)
- Fluvanna County: April 9 to October 31 (205 days, 0 WNV)
- Buchanan County: April 9 to October 29 (203 days, 0 WNV)
West Nile in Frederick County
From 1999 to 2025, CDC ArboNET counted 4 human West Nile cases in Frederick County (3 neuroinvasive) across 3 years. The worst was 2012 with 2; the latest was 2018.
See how the dates are worked out, and when mosquitoes go away for the winter.