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

Mosquito months in Fillmore County

In a normal year mosquito season in Fillmore County, NE starts around April 11 and ends around October 25, 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 Fillmore 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 25.
• 9 West Nile cases since 2016 (last 2024): you should use repellent at dusk June to August, more so if over 60.

Fillmore County against the rest of NE

Fillmore County has the 2nd longest season of 93 NE counties, at 197 days against 200 in Richardson County and 127 in Sioux County. Its mean temperature is 52.5°F.

• Richardson County: April 8 to October 25 (200 days, 3 WNV)
• Douglas County: April 11 to October 23 (195 days, 150 WNV)
• Pawnee County: April 12 to October 24 (195 days, 1 WNV)

West Nile in Fillmore County

From 1999 to 2025, CDC ArboNET counted 39 human West Nile cases in Fillmore County (10 neuroinvasive) across 9 years. The worst was 2003 with 23; the latest was 2024.

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