Mosquito season in Wayne County, IL: when it starts and ends
Mosquito months in Wayne County
In a normal year mosquito season in Wayne County, IL starts around March 27 and ends around November 5, about 32 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Wayne County, and when
- Start tipping out standing water weekly by March 13.
- Book any yard treatment for late March, ahead of the July peak.
- Repellent can go away after November 5.
- 1 West Nile case since 2016 (last 2025): you should use repellent at dusk June to August, more so if over 60.
Wayne County against the rest of IL
Wayne County has the 9th longest season of 102 IL counties, at 223 days against 232 in Pulaski County and 174 in Boone County. Its mean temperature is 56.7°F.
- Edwards County: March 27 to November 5 (223 days, 1 WNV)
- Massac County: March 27 to November 5 (223 days, 4 WNV)
- Franklin County: March 27 to November 4 (222 days, 8 WNV)
- Wabash County: March 28 to November 4 (221 days, 1 WNV)
West Nile in Wayne County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Wayne County (1 neuroinvasive) across 1 year. The worst was 2025 with 1; the latest was 2025.
More: how the dates are worked out · when the season starts across the US.