Mosquito season in Grant County, OK: when it starts and ends
Mosquito months in Grant County
In a normal year mosquito season in Grant County, OK starts around April 1 and ends around November 4, about 31 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Grant County, and when
- Start tipping out standing water weekly by March 18.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after November 4.
- 2 West Nile cases since 2016 (last 2023): you should use repellent at dusk June to September, more so if over 60.
Grant County against the rest of OK
Grant County has the 66th longest season of 77 OK counties, at 217 days against 271 in Choctaw County and 193 in Cimarron County. Its mean temperature is 58.6°F.
- Custer County: April 1 to November 5 (218 days, 1 WNV)
- Beckham County: April 1 to November 4 (217 days, 2 WNV)
- Woods County: April 1 to November 3 (216 days, 1 WNV)
- Pawnee County: March 31 to November 1 (215 days, 1 WNV)
West Nile in Grant County
From 1999 to 2025, CDC ArboNET counted 6 human West Nile cases in Grant County (3 neuroinvasive) across 5 years. The worst was 2005 with 2; the latest was 2023.
Background: when mosquitoes go away for the winter; how the dates are worked out.