Mosquito season in Platte County, MO: when it starts and ends
Mosquito months in Platte County
In a normal year mosquito season in Platte County, MO starts around April 2 and ends around October 30, about 30 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Platte County, and when
- Start tipping out standing water weekly by March 19.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after October 30.
- 3 West Nile cases since 2016 (last 2025): you should use repellent at dusk June to August, more so if over 60.
Platte County against the rest of MO
Platte County has the 56th longest season of 115 MO counties, at 212 days against 242 in Pemiscot County and 187 in Crawford County. Its mean temperature is 54.7°F.
- Cass County: April 2 to October 31 (212 days, 1 WNV)
- Howard County: April 2 to October 31 (212 days, 0 WNV)
- Christian County: April 3 to November 1 (212 days, 0 WNV)
- Johnson County: April 3 to October 31 (211 days, 0 WNV)
West Nile in Platte County
From 1999 to 2025, CDC ArboNET counted 5 human West Nile cases in Platte County (4 neuroinvasive) across 5 years. The worst was 2025 with 1; the latest was 2025.
Background: when mosquitoes go away for the winter; how the dates are worked out.