Mosquito season in Jackson County, MO: when it starts and ends
Mosquito months in Jackson County
In a normal year mosquito season in Jackson County, MO starts around April 1 and ends around October 31, about 30 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Jackson County, and when
- Start tipping out standing water weekly by March 18.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after October 31.
- 21 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to August, and check MO spray notices.
Jackson County against the rest of MO
Jackson County has the 50th longest season of 115 MO counties, at 213 days against 242 in Pemiscot County and 187 in Crawford County. Its mean temperature is 54.7°F.
- St. Francois County: April 1 to November 1 (214 days, 1 WNV)
- Cooper County: April 1 to November 1 (213 days, 0 WNV)
- Pulaski County: April 1 to October 31 (213 days, 2 WNV)
- Bates County: April 2 to November 1 (213 days, 0 WNV)
West Nile in Jackson County
From 1999 to 2025, CDC ArboNET counted 80 human West Nile cases in Jackson County (62 neuroinvasive) across 18 years. The worst was 2007 with 16; the latest was 2025.
Background: reading the West Nile counts; how the dates are worked out.