Mosquito season in Jasper County, IA: when it starts and ends
Mosquito months in Jasper County
In a normal year mosquito season in Jasper County, IA starts around April 18 and ends around October 18, about 26 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Jasper County, and when
- Start tipping out standing water weekly by April 4.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 18.
- 1 West Nile case since 2016 (last 2018): you should use repellent at dusk June to August, more so if over 60.
Jasper County against the rest of IA
Jasper County has the 38th longest season of 99 IA counties, at 183 days against 198 in Des Moines County and 160 in Worth County. Its mean temperature is 48.6°F.
- Union County: April 18 to October 19 (184 days, 0 WNV)
- Black Hawk County: April 18 to October 18 (183 days, 0 WNV)
- Decatur County: April 19 to October 19 (183 days, 0 WNV)
- Boone County: April 18 to October 18 (182 days, 3 WNV)
West Nile in Jasper County
From 1999 to 2025, CDC ArboNET counted 7 human West Nile cases in Jasper County (3 neuroinvasive) across 4 years. The worst was 2003 with 4; the latest was 2018.
More: how the dates are worked out · when the season starts across the US.