Mosquito season in Hamilton County, NE: when it starts and ends
Mosquito months in Hamilton County
In a normal year mosquito season in Hamilton County, NE starts around April 14 and ends around October 22, about 27 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Hamilton County, and when
- Start tipping out standing water weekly by March 31.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 22.
- 15 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to August, and check NE spray notices.
Hamilton County against the rest of NE
Hamilton County has the 12th longest season of 93 NE counties, at 192 days against 200 in Richardson County and 127 in Sioux County. Its mean temperature is 51.3°F.
- Howard County: April 13 to October 22 (192 days, 8 WNV)
- Gage County: April 14 to October 23 (192 days, 6 WNV)
- Jefferson County: April 14 to October 23 (192 days, 0 WNV)
- Harlan County: April 13 to October 22 (191 days, 2 WNV)
West Nile in Hamilton County
From 1999 to 2025, CDC ArboNET counted 96 human West Nile cases in Hamilton County (16 neuroinvasive) across 18 years. The worst was 2003 with 51; the latest was 2025.
More: how the dates are worked out · reading the West Nile counts.