Mosquito season in Highland County, OH: when it starts and ends
Mosquito months in Highland County
In a normal year mosquito season in Highland County, OH starts around April 12 and ends around October 27, about 28 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Highland County, and when
- Start tipping out standing water weekly by March 29.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 27.
- 1 West Nile case since 2016 (last 2023): you should use repellent at dusk June to August, more so if over 60.
Highland County against the rest of OH
Highland County has the 22nd longest season of 88 OH counties, at 198 days against 209 in Gallia County and 177 in Ashtabula County. Its mean temperature is 52.4°F.
- Athens County: April 11 to October 26 (198 days, 1 WNV)
- Darke County: April 11 to October 25 (198 days, 1 WNV)
- Muskingum County: April 13 to October 28 (198 days, 0 WNV)
- Fayette County: April 11 to October 25 (197 days, 0 WNV)
West Nile in Highland County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Highland County (0 neuroinvasive) across 1 year. The worst was 2023 with 1; the latest was 2023.
Background: when mosquitoes go away for the winter; how the dates are worked out.