Mosquito season in Caldwell County, MO: when it starts and ends
Mosquito months in Caldwell County
In a normal year mosquito season in Caldwell County, MO starts around April 13 and ends around October 24, about 28 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Caldwell County, and when
- Start tipping out standing water weekly by March 30.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 24.
- 1 West Nile case since 2016 (last 2022): you should use repellent at dusk June to August, more so if over 60.
Caldwell County against the rest of MO
Caldwell County has the 106th longest season of 115 MO counties, at 194 days against 242 in Pemiscot County and 187 in Crawford County. Its mean temperature is 52°F.
- Nodaway County: April 11 to October 23 (195 days, 0 WNV)
- Adair County: April 12 to October 24 (195 days, 0 WNV)
- Schuyler County: April 13 to October 23 (194 days, 0 WNV)
- Atchison County: April 11 to October 22 (193 days, 0 WNV)
West Nile in Caldwell County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Caldwell County (1 neuroinvasive) across 1 year. The worst was 2022 with 1; the latest was 2022.
More: how the dates are worked out · when mosquitoes go away for the winter.