Mosquito season in Audubon County, IA: when it starts and ends

Mosquito months in Audubon County

In a normal year mosquito season in Audubon County, IA starts around April 22 and ends around October 14, about 25 weeks.

1. Jan
2. Feb
3. Mar
4. Apr
5. May
6. Jun
7. Jul
8. Aug
9. Sep
10. Oct
11. Nov
12. Dec

What to do in Audubon County, and when

• Start tipping out standing water weekly by April 8.
• Book any yard treatment for late April, ahead of the July peak.
• Repellent can go away after October 14.
• 2 West Nile cases since 2016 (last 2019): you should use repellent at dusk July to July, more so if over 60.

Audubon County against the rest of IA

Audubon County has the 67th longest season of 99 IA counties, at 175 days against 198 in Des Moines County and 160 in Worth County. Its mean temperature is 47.1°F.

• Crawford County: April 23 to October 16 (176 days, 2 WNV)
• Poweshiek County: April 23 to October 16 (176 days, 2 WNV)
• Buchanan County: April 22 to October 15 (175 days, 0 WNV)
• Plymouth County: April 22 to October 14 (175 days, 10 WNV)

West Nile in Audubon County

From 1999 to 2025, CDC ArboNET counted 8 human West Nile cases in Audubon County (5 neuroinvasive) across 4 years. The worst was 2003 with 5; the latest was 2019.

See how the dates are worked out, and when mosquitoes go away for the winter.