Mosquito season in Yuma County, CO: when it starts and ends
Mosquito months in Yuma County
In a normal year mosquito season in Yuma County, CO starts around April 29 and ends around October 15, about 24 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Yuma County, and when
- Start tipping out standing water weekly by April 15.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 15.
- 3 West Nile cases since 2016 (last 2021): you should use repellent at dusk June to August, more so if over 60.
Yuma County against the rest of CO
Yuma County has the 21st longest season of 64 CO counties, at 169 days against 200 in Mesa County and 69 in Summit County. Its mean temperature is 51.2°F.
- Cheyenne County: April 28 to October 14 (169 days, 0 WNV)
- Huerfano County: April 29 to October 15 (169 days, 2 WNV)
- Dolores County: May 2 to October 15 (166 days, 0 WNV)
- Otero County: April 29 to October 11 (165 days, 12 WNV)
West Nile in Yuma County
From 1999 to 2025, CDC ArboNET counted 29 human West Nile cases in Yuma County (5 neuroinvasive) across 6 years. The worst was 2003 with 17; the latest was 2021.
Background: when mosquitoes go away for the winter; how the dates are worked out.