Mosquito season in Lyon County, KS: when it starts and ends
Mosquito months in Lyon County
In a normal year mosquito season in Lyon County, KS starts around April 5 and ends around October 29, about 30 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Lyon County, and when
- Start tipping out standing water weekly by March 22.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after October 29.
- No West Nile cases since 2016, so bites in Lyon County are a nuisance; check window screens.
Lyon County against the rest of KS
Lyon County has the 38th longest season of 105 KS counties, at 207 days against 227 in Cherokee County and 178 in Thomas County. Its mean temperature is 54.2°F.
- Rice County: April 6 to October 31 (208 days, 2 WNV)
- Atchison County: April 4 to October 29 (207 days, 2 WNV)
- Saline County: April 7 to October 31 (207 days, 9 WNV)
- Wabaunsee County: April 6 to October 29 (206 days, 1 WNV)
West Nile in Lyon County
From 1999 to 2025, CDC ArboNET counted 2 human West Nile cases in Lyon County (2 neuroinvasive) across 2 years. The worst was 2015 with 1; the latest was 2015.
Background: when mosquitoes go away for the winter; how the dates are worked out.