Mosquito season in Dallas County, MO: when it starts and ends
Mosquito months in Dallas County
In a normal year mosquito season in Dallas County, MO starts around April 9 and ends around October 25, about 28 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Dallas County, and when
- Start tipping out standing water weekly by March 26.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after October 25.
- 1 West Nile case since 2016 (last 2023): you should use repellent at dusk June to August, more so if over 60.
Dallas County against the rest of MO
Dallas County has the 94th longest season of 115 MO counties, at 199 days against 242 in Pemiscot County and 187 in Crawford County. Its mean temperature is 55.1°F.
- Grundy County: April 9 to October 26 (200 days, 1 WNV)
- Monroe County: April 11 to October 28 (200 days, 0 WNV)
- Knox County: April 9 to October 25 (199 days, 0 WNV)
- Clinton County: April 10 to October 26 (199 days, 1 WNV)
West Nile in Dallas County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Dallas County (1 neuroinvasive) across 1 year. The worst was 2023 with 1; the latest was 2023.
See how the dates are worked out, and when the season starts across the US.