Mosquito season in Thomas County, KS: when it starts and ends
Mosquito months in Thomas County
In a normal year mosquito season in Thomas County, KS starts around April 23 and ends around October 18, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Thomas County, and when
- Start tipping out standing water weekly by April 9.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 18.
- 4 West Nile cases since 2016 (last 2025): you should use repellent at dusk June to August, more so if over 60.
Thomas County against the rest of KS
Thomas County has the 105th longest season of 105 KS counties, at 178 days against 227 in Cherokee County and 178 in Thomas County. Its mean temperature is 51.8°F.
- Sherman County: April 23 to October 19 (179 days, 5 WNV)
- Rawlins County: April 22 to October 17 (178 days, 2 WNV)
West Nile in Thomas County
From 1999 to 2025, CDC ArboNET counted 9 human West Nile cases in Thomas County (4 neuroinvasive) across 7 years. The worst was 2014 with 2; the latest was 2025.
See how the dates are worked out, and reading the West Nile counts.