Mosquito season in Prowers County, CO: when it starts and ends
Mosquito months in Prowers County
In a normal year mosquito season in Prowers County, CO starts around April 18 and ends around October 20, about 26 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Prowers County, and when
- Start tipping out standing water weekly by April 4.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 20.
- 9 West Nile cases since 2016 (last 2023): you should use repellent at dusk June to August, more so if over 60.
Prowers County against the rest of CO
Prowers County has the 3rd longest season of 64 CO counties, at 185 days against 200 in Mesa County and 69 in Summit County. Its mean temperature is 53.5°F.
- Mesa County: April 8 to October 25 (200 days, 29 WNV)
- Bent County: April 18 to October 21 (186 days, 3 WNV)
- Kiowa County: April 19 to October 21 (185 days, 2 WNV)
- Broomfield County: April 20 to October 20 (183 days, 35 WNV)
West Nile in Prowers County
From 1999 to 2025, CDC ArboNET counted 95 human West Nile cases in Prowers County (13 neuroinvasive) across 15 years. The worst was 2003 with 42; the latest was 2023.
Background: reading the West Nile counts; how the dates are worked out.