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

Mosquito months in Nance County

In a normal year mosquito season in Nance County, NE starts around April 20 and ends around October 15, about 25 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 Nance County, and when

• Start tipping out standing water weekly by April 6.
• Book any yard treatment for mid April, ahead of the July peak.
• Repellent can go away after October 15.
• 4 West Nile cases since 2016 (last 2025): you should use repellent at dusk June to August, more so if over 60.

Nance County against the rest of NE

Nance County has the 49th longest season of 93 NE counties, at 178 days against 200 in Richardson County and 127 in Sioux County. Its mean temperature is 49.8°F.

• Madison County: April 20 to October 16 (179 days, 18 WNV)
• Sherman County: April 21 to October 17 (179 days, 2 WNV)
• Pierce County: April 21 to October 16 (178 days, 4 WNV)
• Thurston County: April 21 to October 16 (178 days, 2 WNV)

West Nile in Nance County

From 1999 to 2025, CDC ArboNET counted 15 human West Nile cases in Nance County (1 neuroinvasive) across 9 years. The worst was 2003 with 7; the latest was 2025.

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