Mosquito season in Bureau County, IL: when it starts and ends
Mosquito months in Bureau County
In a normal year mosquito season in Bureau County, IL starts around April 15 and ends around October 20, about 27 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Bureau County, and when
- Start tipping out standing water weekly by April 1.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 20.
- No West Nile cases since 2016, so bites in Bureau County are a nuisance; check window screens.
Bureau County against the rest of IL
Bureau County has the 88th longest season of 102 IL counties, at 188 days against 232 in Pulaski County and 174 in Boone County. Its mean temperature is 49.8°F.
- Stark County: April 15 to October 21 (189 days, 0 WNV)
- Cook County: April 20 to October 26 (189 days, 532 WNV)
- DuPage County: April 18 to October 22 (187 days, 99 WNV)
- Kendall County: April 18 to October 21 (186 days, 4 WNV)
West Nile in Bureau County
From 1999 to 2025, CDC ArboNET counted 2 human West Nile cases in Bureau County (1 neuroinvasive) across 2 years. The worst was 2007 with 1; the latest was 2007.
See how the dates are worked out, and when the season starts across the US.