Mosquito season in Worth County, MO: when it starts and ends
Mosquito months in Worth County
In a normal year mosquito season in Worth County, MO starts around April 14 and ends around October 21, about 27 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Worth County, and when
- Start tipping out standing water weekly by March 31.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 21.
- No West Nile cases since 2016, so bites in Worth County are a nuisance; check window screens.
Worth County against the rest of MO
Worth County has the 114th longest season of 115 MO counties, at 190 days against 242 in Pemiscot County and 187 in Crawford County. Its mean temperature is 50.5°F.
- Mercer County: April 14 to October 23 (192 days, 0 WNV)
- Sullivan County: April 14 to October 22 (191 days, 0 WNV)
- Crawford County: April 14 to October 18 (187 days, 0 WNV)
West Nile in Worth County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Worth County (1 neuroinvasive) across 1 year. The worst was 2003 with 1; the latest was 2003.
See how the dates are worked out, and when mosquitoes go away for the winter.