Mosquito season in Douglas County, NE: when it starts and ends

Mosquito months in Douglas County

In a normal year mosquito season in Douglas County, NE starts around April 11 and ends around October 23, about 28 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 Douglas County, and when

• Start tipping out standing water weekly by March 28.
• Book any yard treatment for mid April, ahead of the July peak.
• Repellent can go away after October 23.
• 150 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to August, and check NE spray notices.

Douglas County against the rest of NE

Douglas County has the 3rd longest season of 93 NE counties, at 195 days against 200 in Richardson County and 127 in Sioux County. Its mean temperature is 51.3°F.

• Richardson County: April 8 to October 25 (200 days, 3 WNV)
• Fillmore County: April 11 to October 25 (197 days, 9 WNV)
• Pawnee County: April 12 to October 24 (195 days, 1 WNV)
• Thayer County: April 13 to October 23 (193 days, 7 WNV)

West Nile in Douglas County

From 1999 to 2025, CDC ArboNET counted 332 human West Nile cases in Douglas County (146 neuroinvasive) across 24 years. The worst was 2018 with 71; the latest was 2025.

See how the dates are worked out, and reading the West Nile counts.