Mosquito season in Bullitt County, KY: when it starts and ends
Mosquito months in Bullitt County
In a normal year mosquito season in Bullitt County, KY starts around April 4 and ends around November 3, about 30 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Bullitt County, and when
- Start tipping out standing water weekly by March 21.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after November 3.
- 1 West Nile case since 2016 (last 2025): you should use repellent at dusk June to August, more so if over 60.
Bullitt County against the rest of KY
Bullitt County has the 57th longest season of 120 KY counties, at 213 days against 249 in Lyon County and 180 in Shelby County. Its mean temperature is 57.4°F.
- Henry County: April 1 to October 31 (214 days, 1 WNV)
- Anderson County: April 3 to November 3 (214 days, 1 WNV)
- Larue County: April 4 to November 3 (213 days, 0 WNV)
- Wayne County: April 4 to November 3 (213 days, 1 WNV)
West Nile in Bullitt County
From 1999 to 2025, CDC ArboNET counted 4 human West Nile cases in Bullitt County (2 neuroinvasive) across 3 years. The worst was 2011 with 2; the latest was 2025.
Background: when mosquitoes go away for the winter; how the dates are worked out.