Mosquito season in Sumner County, KS: when it starts and ends
Mosquito months in Sumner County
In a normal year mosquito season in Sumner County, KS starts around April 3 and ends around November 5, about 31 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Sumner County, and when
- Start tipping out standing water weekly by March 20.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after November 5.
- 1 West Nile case since 2016 (last 2025): you should use repellent at dusk June to September, more so if over 60.
Sumner County against the rest of KS
Sumner County has the 14th longest season of 105 KS counties, at 216 days against 227 in Cherokee County and 178 in Thomas County. Its mean temperature is 56.9°F.
- Wilson County: April 1 to November 3 (216 days, 0 WNV)
- Comanche County: April 3 to November 5 (216 days, 0 WNV)
- Johnson County: April 1 to November 1 (214 days, 25 WNV)
- Coffey County: April 2 to November 2 (214 days, 0 WNV)
West Nile in Sumner County
From 1999 to 2025, CDC ArboNET counted 5 human West Nile cases in Sumner County (2 neuroinvasive) across 3 years. The worst was 2012 with 3; the latest was 2025.
Background: when mosquitoes go away for the winter; how the dates are worked out.