Mosquito season in Ellis County, OK: when it starts and ends
Mosquito months in Ellis County
In a normal year mosquito season in Ellis County, OK starts around April 5 and ends around November 4, about 30 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Ellis County, and when
- Start tipping out standing water weekly by March 22.
- 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.
Ellis County against the rest of OK
Ellis County has the 71st longest season of 77 OK counties, at 213 days against 271 in Choctaw County and 193 in Cimarron County. Its mean temperature is 57.7°F.
- Washington County: April 1 to November 2 (215 days, 4 WNV)
- Blaine County: April 3 to November 4 (215 days, 1 WNV)
- Delaware County: April 3 to October 30 (210 days, 1 WNV)
- Harper County: April 7 to November 1 (208 days, 3 WNV)
West Nile in Ellis County
From 1999 to 2025, CDC ArboNET counted 9 human West Nile cases in Ellis County (2 neuroinvasive) across 7 years. The worst was 2023 with 2; the latest was 2023.
Background: when the season starts across the US; how the dates are worked out.