Mosquito season in Pottawattamie County, IA: when it starts and ends
Mosquito months in Pottawattamie County
In a normal year mosquito season in Pottawattamie County, IA starts around April 16 and ends around October 21, about 27 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Pottawattamie County, and when
- Start tipping out standing water weekly by April 2.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 21.
- 18 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to August, and check IA spray notices.
Pottawattamie County against the rest of IA
Pottawattamie County has the 21st longest season of 99 IA counties, at 188 days against 198 in Des Moines County and 160 in Worth County. Its mean temperature is 49.8°F.
- Jefferson County: April 15 to October 20 (188 days, 0 WNV)
- Louisa County: April 15 to October 20 (188 days, 0 WNV)
- Wayne County: April 16 to October 20 (188 days, 2 WNV)
- Cedar County: April 16 to October 20 (187 days, 2 WNV)
West Nile in Pottawattamie County
From 1999 to 2025, CDC ArboNET counted 46 human West Nile cases in Pottawattamie County (32 neuroinvasive) across 18 years. The worst was 2018 with 12; the latest was 2025.
More: how the dates are worked out · reading the West Nile counts.