Mosquito season in Osage County, KS: when it starts and ends
Mosquito months in Osage County
In a normal year mosquito season in Osage County, KS starts around April 2 and ends around November 1, about 30 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Osage 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 November 1.
- No West Nile cases since 2016, so bites in Osage County are a nuisance; check window screens.
Osage County against the rest of KS
Osage County has the 20th longest season of 105 KS counties, at 213 days against 227 in Cherokee County and 178 in Thomas County. Its mean temperature is 55°F.
- Morris County: April 1 to October 31 (213 days, 0 WNV)
- Linn County: April 2 to November 1 (213 days, 1 WNV)
- Butler County: April 3 to November 2 (213 days, 6 WNV)
- Barber County: April 2 to October 31 (212 days, 3 WNV)
West Nile in Osage County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Osage County (0 neuroinvasive) across 1 year. The worst was 2015 with 1; the latest was 2015.
Background: when the season starts across the US; how the dates are worked out.