Mosquito season in Dewey County, OK: when it starts and ends
Mosquito months in Dewey County
In a normal year mosquito season in Dewey County, OK starts around April 8 and ends around October 29, about 29 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Dewey County, and when
- Start tipping out standing water weekly by March 25.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after October 29.
- 1 West Nile case since 2016 (last 2023): you should use repellent at dusk June to September, more so if over 60.
Dewey County against the rest of OK
Dewey County has the 75th longest season of 77 OK counties, at 204 days against 271 in Choctaw County and 193 in Cimarron County. Its mean temperature is 58.4°F.
- Harper County: April 7 to November 1 (208 days, 3 WNV)
- Texas County: April 8 to November 1 (207 days, 4 WNV)
- Beaver County: April 10 to October 29 (202 days, 5 WNV)
- Cimarron County: April 15 to October 25 (193 days, 0 WNV)
West Nile in Dewey County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Dewey County (1 neuroinvasive) across 1 year. The worst was 2023 with 1; the latest was 2023.
Background: when mosquitoes go away for the winter; how the dates are worked out.