Mosquito season in Sarpy County, NE: when it starts and ends
Mosquito months in Sarpy County
In a normal year mosquito season in Sarpy 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 Sarpy 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.
- 56 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to August, and check NE spray notices.
Sarpy County against the rest of NE
Sarpy County has the 15th longest season of 93 NE counties, at 191 days against 200 in Richardson County and 127 in Sioux County. Its mean temperature is 50.7°F.
- Jefferson County: April 14 to October 23 (192 days, 0 WNV)
- Harlan County: April 13 to October 22 (191 days, 2 WNV)
- York County: April 14 to October 22 (191 days, 12 WNV)
- Lancaster County: April 15 to October 22 (190 days, 91 WNV)
West Nile in Sarpy County
From 1999 to 2025, CDC ArboNET counted 97 human West Nile cases in Sarpy County (44 neuroinvasive) across 22 years. The worst was 2018 with 33; the latest was 2025.
Background: reading the West Nile counts; how the dates are worked out.