Mosquito season in Logan County, CO: when it starts and ends
Mosquito months in Logan County
In a normal year mosquito season in Logan County, CO starts around April 19 and ends around October 17, about 26 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Logan 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 17.
- 19 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to August, and check CO spray notices.
Logan County against the rest of CO
Logan County has the 7th longest season of 64 CO counties, at 181 days against 200 in Mesa County and 69 in Summit County. Its mean temperature is 51.1°F.
- Broomfield County: April 20 to October 20 (183 days, 35 WNV)
- Pueblo County: April 19 to October 18 (182 days, 37 WNV)
- Denver County: April 22 to October 18 (179 days, 189 WNV)
- Las Animas County: April 23 to October 18 (178 days, 2 WNV)
West Nile in Logan County
From 1999 to 2025, CDC ArboNET counted 144 human West Nile cases in Logan County (30 neuroinvasive) across 17 years. The worst was 2003 with 84; the latest was 2025.
Background: reading the West Nile counts; how the dates are worked out.