Mosquito season in Atchison County, MO: when it starts and ends
Mosquito months in Atchison County
In a normal year mosquito season in Atchison County, MO starts around April 11 and ends around October 22, about 28 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Atchison County, and when
- Start tipping out standing water weekly by March 28.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 22.
- No West Nile cases since 2016, so bites in Atchison County are a nuisance; check window screens.
Atchison County against the rest of MO
Atchison County has the 108th longest season of 115 MO counties, at 193 days against 242 in Pemiscot County and 187 in Crawford County. Its mean temperature is 51.1°F.
- Caldwell County: April 13 to October 24 (194 days, 1 WNV)
- Schuyler County: April 13 to October 23 (194 days, 0 WNV)
- Gasconade County: April 14 to October 24 (193 days, 0 WNV)
- Putnam County: April 13 to October 22 (192 days, 0 WNV)
West Nile in Atchison County
CDC ArboNET lists no human West Nile cases for Atchison County from 1999 to 2025, though virus turned up in birds, mosquitoes or horses in 1 of those years.
See how the dates are worked out, and when the season starts across the US.