Mosquito season in Mercer County, KY: when it starts and ends
Mosquito months in Mercer County
In a normal year mosquito season in Mercer County, KY starts around March 29 and ends around November 4, about 31 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Mercer County, and when
- Start tipping out standing water weekly by March 15.
- Book any yard treatment for late March, ahead of the July peak.
- Repellent can go away after November 4.
- No West Nile cases since 2016, so bites in Mercer County are a nuisance; check window screens.
Mercer County against the rest of KY
Mercer County has the 27th longest season of 120 KY counties, at 220 days against 249 in Lyon County and 180 in Shelby County. Its mean temperature is 56.3°F.
- Jessamine County: March 29 to November 5 (221 days, 0 WNV)
- Webster County: March 29 to November 5 (221 days, 0 WNV)
- Grant County: March 31 to November 6 (220 days, 0 WNV)
- Carroll County: March 29 to November 3 (219 days, 0 WNV)
West Nile in Mercer County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Mercer County (0 neuroinvasive) across 1 year. The worst was 2002 with 1; the latest was 2002.
More: how the dates are worked out · when mosquitoes go away for the winter.