Mosquito season in Washington County, KY: when it starts and ends
Mosquito months in Washington County
In a normal year mosquito season in Washington County, KY starts around March 31 and ends around November 5, about 31 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Washington County, and when
- Start tipping out standing water weekly by March 17.
- Book any yard treatment for late March, ahead of the July peak.
- Repellent can go away after November 5.
- No West Nile cases since 2016, so bites in Washington County are a nuisance; check window screens.
Washington County against the rest of KY
Washington County has the 31st longest season of 120 KY counties, at 219 days against 249 in Lyon County and 180 in Shelby County. Its mean temperature is 56.3°F.
- Carroll County: March 29 to November 3 (219 days, 0 WNV)
- Nelson County: March 31 to November 5 (219 days, 1 WNV)
- Fayette County: March 31 to November 4 (218 days, 10 WNV)
- Henderson County: March 31 to November 4 (218 days, 3 WNV)
West Nile in Washington County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Washington County (0 neuroinvasive) across 1 year. The worst was 2002 with 1; the latest was 2002.
Background: when mosquitoes go away for the winter; how the dates are worked out.