Mosquito season in Pueblo County, CO: when it starts and ends
Mosquito months in Pueblo County
In a normal year mosquito season in Pueblo County, CO starts around April 19 and ends around October 18, about 26 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Pueblo County, and when
- Start tipping out standing water weekly by April 5.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 18.
- 37 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to August, and check CO spray notices.
Pueblo County against the rest of CO
Pueblo County has the 6th longest season of 64 CO counties, at 182 days against 200 in Mesa County and 69 in Summit County. Its mean temperature is 53.2°F.
- Kiowa County: April 19 to October 21 (185 days, 2 WNV)
- Broomfield County: April 20 to October 20 (183 days, 35 WNV)
- Logan County: April 19 to October 17 (181 days, 19 WNV)
- Denver County: April 22 to October 18 (179 days, 189 WNV)
West Nile in Pueblo County
From 1999 to 2025, CDC ArboNET counted 280 human West Nile cases in Pueblo County (88 neuroinvasive) across 19 years. The worst was 2003 with 183; the latest was 2025.
More: how the dates are worked out · reading the West Nile counts.