Mosquito season in Washakie County, WY: when it starts and ends
Mosquito months in Washakie County
In a normal year mosquito season in Washakie County, WY starts around May 9 and ends around September 28, about 20 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Washakie County, and when
- Start tipping out standing water weekly by April 25.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after September 28.
- 3 West Nile cases since 2016 (last 2023): you should use repellent at dusk July to July, more so if over 60.
Washakie County against the rest of WY
Washakie County has the 13th longest season of 23 WY counties, at 142 days against 163 in Big Horn County and 75 in Teton County. Its mean temperature is 44.4°F.
- Sweetwater County: May 12 to October 2 (144 days, 0 WNV)
- Natrona County: May 11 to October 1 (143 days, 12 WNV)
- Johnson County: May 11 to September 30 (142 days, 0 WNV)
- Crook County: May 14 to October 1 (140 days, 1 WNV)
West Nile in Washakie County
From 1999 to 2025, CDC ArboNET counted 11 human West Nile cases in Washakie County (5 neuroinvasive) across 7 years. The worst was 2007 with 3; the latest was 2023.
Background: when the season starts across the US; how the dates are worked out.