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

Mosquito months in Valley County

In a normal year mosquito season in Valley County, NE starts around April 25 and ends around October 12, about 24 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 Valley County, and when

• Start tipping out standing water weekly by April 11.
• Book any yard treatment for late April, ahead of the July peak.
• Repellent can go away after October 12.
• 5 West Nile cases since 2016 (last 2022): you should use repellent at dusk July to August, more so if over 60.

Valley County against the rest of NE

Valley County has the 67th longest season of 93 NE counties, at 170 days against 200 in Richardson County and 127 in Sioux County. Its mean temperature is 48.9°F.

• Boyd County: April 26 to October 14 (171 days, 1 WNV)
• Holt County: April 25 to October 13 (170 days, 12 WNV)
• Greeley County: April 25 to October 11 (169 days, 0 WNV)
• Furnas County: April 26 to October 12 (169 days, 3 WNV)

West Nile in Valley County

From 1999 to 2025, CDC ArboNET counted 40 human West Nile cases in Valley County (4 neuroinvasive) across 14 years. The worst was 2003 with 20; the latest was 2022.

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