Mosquito season in Kendall County, IL: when it starts and ends
Mosquito months in Kendall County
In a normal year mosquito season in Kendall County, IL starts around April 18 and ends around October 21, about 27 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Kendall 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 October 21.
- 4 West Nile cases since 2016 (last 2023): you should use repellent at dusk June to August, more so if over 60.
Kendall County against the rest of IL
Kendall County has the 90th longest season of 102 IL counties, at 186 days against 232 in Pulaski County and 174 in Boone County. Its mean temperature is 50°F.
- Bureau County: April 15 to October 20 (188 days, 0 WNV)
- DuPage County: April 18 to October 22 (187 days, 99 WNV)
- Kane County: April 19 to October 20 (184 days, 35 WNV)
- Ogle County: April 19 to October 19 (183 days, 1 WNV)
West Nile in Kendall County
From 1999 to 2025, CDC ArboNET counted 16 human West Nile cases in Kendall County (10 neuroinvasive) across 11 years. The worst was 2005 with 3; the latest was 2023.
More: how the dates are worked out · reading the West Nile counts.