Mosquito season in Ida County, IA: when it starts and ends
Mosquito months in Ida County
In a normal year mosquito season in Ida County, IA starts around April 21 and ends around October 15, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Ida County, and when
- Start tipping out standing water weekly by April 7.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 15.
- 3 West Nile cases since 2016 (last 2025): you should use repellent at dusk June to August, more so if over 60.
Ida County against the rest of IA
Ida County has the 56th longest season of 99 IA counties, at 177 days against 198 in Des Moines County and 160 in Worth County. Its mean temperature is 47.4°F.
- Tama County: April 21 to October 16 (178 days, 3 WNV)
- Dubuque County: April 21 to October 15 (177 days, 2 WNV)
- Calhoun County: April 22 to October 16 (177 days, 2 WNV)
- Winneshiek County: April 22 to October 16 (177 days, 0 WNV)
West Nile in Ida County
From 1999 to 2025, CDC ArboNET counted 6 human West Nile cases in Ida County (3 neuroinvasive) across 5 years. The worst was 2003 with 2; the latest was 2025.
Background: when mosquitoes go away for the winter; how the dates are worked out.