Mosquito season in Harrison County, KY: when it starts and ends
Mosquito months in Harrison County
In a normal year mosquito season in Harrison County, KY starts around April 5 and ends around November 1, about 30 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Harrison County, and when
- Start tipping out standing water weekly by March 22.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after November 1.
- 1 West Nile case since 2016 (last 2025): you should use repellent at dusk June to August, more so if over 60.
Harrison County against the rest of KY
Harrison County has the 75th longest season of 120 KY counties, at 210 days against 249 in Lyon County and 180 in Shelby County. Its mean temperature is 55°F.
- Breathitt County: April 5 to November 1 (210 days, 1 WNV)
- Garrard County: April 5 to November 1 (210 days, 0 WNV)
- Lincoln County: April 5 to November 1 (210 days, 0 WNV)
- Martin County: April 5 to November 1 (210 days, 0 WNV)
West Nile in Harrison County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Harrison County (1 neuroinvasive) across 1 year. The worst was 2025 with 1; the latest was 2025.
More: how the dates are worked out · when mosquitoes go away for the winter.