Mosquito season in Keith County, NE: when it starts and ends
Mosquito months in Keith County
In a normal year mosquito season in Keith County, NE starts around April 22 and ends around October 17, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Keith County, and when
- Start tipping out standing water weekly by April 8.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 17.
- 9 West Nile cases since 2016 (last 2025): you should use repellent at dusk July to August, more so if over 60.
Keith County against the rest of NE
Keith County has the 54th longest season of 93 NE counties, at 178 days against 200 in Richardson County and 127 in Sioux County. Its mean temperature is 50.1°F.
- Wayne County: April 21 to October 16 (178 days, 3 WNV)
- Hayes County: April 22 to October 17 (178 days, 1 WNV)
- Webster County: April 22 to October 16 (177 days, 2 WNV)
- Boone County: April 22 to October 15 (176 days, 7 WNV)
West Nile in Keith County
From 1999 to 2025, CDC ArboNET counted 65 human West Nile cases in Keith County (13 neuroinvasive) across 16 years. The worst was 2003 with 34; the latest was 2025.
More: how the dates are worked out · reading the West Nile counts.