Mosquito season in Ottawa County, OK: when it starts and ends

Mosquito months in Ottawa County

In a normal year mosquito season in Ottawa County, OK starts around March 25 and ends around November 5, about 32 weeks.

1. Jan
2. Feb
3. Mar
4. Apr
5. May
6. Jun
7. Jul
8. Aug
9. Sep
10. Oct
11. Nov
12. Dec

What to do in Ottawa County, and when

• Start tipping out standing water weekly by March 11.
• Book any yard treatment for late March, ahead of the July peak.
• Repellent can go away after November 5.
• 1 West Nile case since 2016 (last 2024): you should use repellent at dusk June to September, more so if over 60.

Ottawa County against the rest of OK

Ottawa County has the 53rd longest season of 77 OK counties, at 225 days against 271 in Choctaw County and 193 in Cimarron County. Its mean temperature is 58.6°F.

• Canadian County: March 26 to November 7 (226 days, 13 WNV)
• Craig County: March 25 to November 5 (225 days, 0 WNV)
• Lincoln County: March 28 to November 7 (224 days, 1 WNV)
• Osage County: March 28 to November 6 (223 days, 1 WNV)

West Nile in Ottawa County

From 1999 to 2025, CDC ArboNET counted 7 human West Nile cases in Ottawa County (6 neuroinvasive) across 6 years. The worst was 2007 with 2; the latest was 2024.

See how the dates are worked out, and when mosquitoes go away for the winter.