Mosquito season in Linn County, MO: when it starts and ends
Mosquito months in Linn County
In a normal year mosquito season in Linn County, MO starts around April 7 and ends around October 25, about 29 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Linn County, and when
- Start tipping out standing water weekly by March 24.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after October 25.
- No West Nile cases since 2016, so bites in Linn County are a nuisance; check window screens.
Linn County against the rest of MO
Linn County has the 86th longest season of 115 MO counties, at 201 days against 242 in Pemiscot County and 187 in Crawford County. Its mean temperature is 52.4°F.
- Clay County: April 8 to October 27 (202 days, 4 WNV)
- Lewis County: April 8 to October 27 (202 days, 0 WNV)
- Andrew County: April 8 to October 26 (201 days, 0 WNV)
- Livingston County: April 8 to October 26 (201 days, 1 WNV)
West Nile in Linn County
From 1999 to 2025, CDC ArboNET counted 3 human West Nile cases in Linn County (2 neuroinvasive) across 3 years. The worst was 2015 with 1; the latest was 2015.
More: how the dates are worked out · when the season starts across the US.