Mosquito season in Lake County, OH: when it starts and ends
Mosquito months in Lake County
In a normal year mosquito season in Lake County, OH starts around April 18 and ends around November 1, about 28 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Lake County, and when
- Start tipping out standing water weekly by April 4.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after November 1.
- 5 West Nile cases since 2016 (last 2025): you should use repellent at dusk July to August, more so if over 60.
Lake County against the rest of OH
Lake County has the 27th longest season of 88 OH counties, at 197 days against 209 in Gallia County and 177 in Ashtabula County. Its mean temperature is 52.3°F.
- Crawford County: April 13 to October 26 (197 days, 0 WNV)
- Cuyahoga County: April 17 to October 31 (197 days, 35 WNV)
- Meigs County: April 13 to October 26 (196 days, 1 WNV)
- Monroe County: April 13 to October 25 (195 days, 0 WNV)
West Nile in Lake County
From 1999 to 2025, CDC ArboNET counted 16 human West Nile cases in Lake County (9 neuroinvasive) across 8 years. The worst was 2002 with 6; the latest was 2025.
Background: reading the West Nile counts; how the dates are worked out.