Mosquito season in Woodbury County, IA: when it starts and ends
Mosquito months in Woodbury County
In a normal year mosquito season in Woodbury County, IA starts around April 20 and ends around October 15, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Woodbury County, and when
- Start tipping out standing water weekly by April 6.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 15.
- 18 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to August, and check IA spray notices.
Woodbury County against the rest of IA
Woodbury County has the 51st longest season of 99 IA counties, at 178 days against 198 in Des Moines County and 160 in Worth County. Its mean temperature is 48°F.
- Jackson County: April 21 to October 17 (179 days, 0 WNV)
- Madison County: April 20 to October 15 (178 days, 0 WNV)
- Jones County: April 21 to October 15 (178 days, 1 WNV)
- Palo Alto County: April 21 to October 16 (178 days, 1 WNV)
West Nile in Woodbury County
From 1999 to 2025, CDC ArboNET counted 60 human West Nile cases in Woodbury County (22 neuroinvasive) across 17 years. The worst was 2003 with 15; the latest was 2025.
More: how the dates are worked out · reading the West Nile counts.