Mosquito season in Jefferson County, OK: when it starts and ends
Mosquito months in Jefferson County
In a normal year mosquito season in Jefferson County, OK starts around March 13 and ends around November 14, about 35 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Jefferson County, and when
- Start tipping out standing water weekly by February 27.
- Book any yard treatment for mid March, ahead of the July peak.
- Repellent can go away after November 14.
- No West Nile cases since 2016, so bites in Jefferson County are a nuisance; check window screens.
Jefferson County against the rest of OK
Jefferson County has the 11th longest season of 77 OK counties, at 246 days against 271 in Choctaw County and 193 in Cimarron County. Its mean temperature is 63.6°F.
- Stephens County: March 12 to November 16 (249 days, 8 WNV)
- Atoka County: March 12 to November 14 (247 days, 0 WNV)
- Johnston County: March 13 to November 14 (246 days, 0 WNV)
- McCurtain County: March 13 to November 14 (246 days, 0 WNV)
West Nile in Jefferson County
From 1999 to 2025, CDC ArboNET counted 2 human West Nile cases in Jefferson County (2 neuroinvasive) across 2 years. The worst was 2009 with 1; the latest was 2009.
Background: when mosquitoes go away for the winter; how the dates are worked out.