Mosquito season in Cerro Gordo County, IA: when it starts and ends
Mosquito months in Cerro Gordo County
In a normal year mosquito season in Cerro Gordo County, IA starts around April 25 and ends around October 11, about 24 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Cerro Gordo County, and when
- Start tipping out standing water weekly by April 11.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 11.
- No West Nile cases since 2016, so bites in Cerro Gordo County are a nuisance; check window screens.
Cerro Gordo County against the rest of IA
Cerro Gordo County has the 88th longest season of 99 IA counties, at 169 days against 198 in Des Moines County and 160 in Worth County. Its mean temperature is 45.6°F.
- Lyon County: April 25 to October 12 (170 days, 19 WNV)
- Kossuth County: April 26 to October 12 (170 days, 3 WNV)
- Hancock County: April 26 to October 12 (169 days, 1 WNV)
- Mitchell County: April 26 to October 11 (168 days, 1 WNV)
West Nile in Cerro Gordo County
From 1999 to 2025, CDC ArboNET counted 6 human West Nile cases in Cerro Gordo County (6 neuroinvasive) across 4 years. The worst was 2003 with 3; the latest was 2011.
Background: when the season starts across the US; how the dates are worked out.