Mosquito season in Washington County, OK: when it starts and ends
Mosquito months in Washington County
In a normal year mosquito season in Washington County, OK starts around April 1 and ends around November 2, about 31 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Washington 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 2.
- 4 West Nile cases since 2016 (last 2023): you should use repellent at dusk June to September, more so if over 60.
Washington County against the rest of OK
Washington County has the 69th longest season of 77 OK counties, at 215 days against 271 in Choctaw County and 193 in Cimarron County. Its mean temperature is 58.3°F.
- Woods County: April 1 to November 3 (216 days, 1 WNV)
- Pawnee County: March 31 to November 1 (215 days, 1 WNV)
- Blaine County: April 3 to November 4 (215 days, 1 WNV)
- Ellis County: April 5 to November 4 (213 days, 2 WNV)
West Nile in Washington County
From 1999 to 2025, CDC ArboNET counted 8 human West Nile cases in Washington County (6 neuroinvasive) across 4 years. The worst was 2012 with 3; the latest was 2023.
More: how the dates are worked out · reading the West Nile counts.