Mosquito season in Ellis County, KS: when it starts and ends

Mosquito months in Ellis County

In a normal year mosquito season in Ellis County, KS starts around April 9 and ends around October 29, about 29 weeks.

1. Jan
2. Feb
3. Mar
4. Apr
5. May
6. Jun
7. Jul
8. Aug
9. Sep
10. Oct
11. Nov
12. Dec

What to do in Ellis County, and when

• Start tipping out standing water weekly by March 26.
• Book any yard treatment for early April, ahead of the July peak.
• Repellent can go away after October 29.
• 5 West Nile cases since 2016 (last 2021): you should use repellent at dusk June to August, more so if over 60.

Ellis County against the rest of KS

Ellis County has the 53rd longest season of 105 KS counties, at 203 days against 227 in Cherokee County and 178 in Thomas County. Its mean temperature is 54.9°F.

• Pottawatomie County: April 8 to October 28 (203 days, 1 WNV)
• Edwards County: April 9 to October 29 (203 days, 0 WNV)
• Meade County: April 9 to October 29 (203 days, 5 WNV)
• Doniphan County: April 8 to October 27 (202 days, 1 WNV)

West Nile in Ellis County

From 1999 to 2025, CDC ArboNET counted 11 human West Nile cases in Ellis County (8 neuroinvasive) across 8 years. The worst was 2002 with 3; the latest was 2021.

See how the dates are worked out, and reading the West Nile counts.