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

Mosquito months in Clark County

In a normal year mosquito season in Clark County, KS starts around April 10 and ends around October 27, 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 Clark County, and when

• Start tipping out standing water weekly by March 27.
• Book any yard treatment for early April, ahead of the July peak.
• Repellent can go away after October 27.
• No West Nile cases since 2016, so bites in Clark County are a nuisance; check window screens.

Clark County against the rest of KS

Clark County has the 67th longest season of 105 KS counties, at 200 days against 227 in Cherokee County and 178 in Thomas County. Its mean temperature is 57°F.

• Riley County: April 10 to October 28 (201 days, 1 WNV)
• Nemaha County: April 9 to October 26 (200 days, 0 WNV)
• Ford County: April 11 to October 28 (200 days, 9 WNV)
• Haskell County: April 12 to October 29 (200 days, 3 WNV)

West Nile in Clark County

From 1999 to 2025, CDC ArboNET counted 6 human West Nile cases in Clark County (3 neuroinvasive) across 4 years. The worst was 2014 with 2; the latest was 2014.

See how the dates are worked out, and when the season starts across the US.