Mosquito season in Washington County, NE: when it starts and ends
Mosquito months in Washington County
In a normal year mosquito season in Washington County, NE starts around April 15 and ends around October 21, about 27 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Washington County, and when
- Start tipping out standing water weekly by April 1.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 21.
- 17 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to August, and check NE spray notices.
Washington County against the rest of NE
Washington County has the 20th longest season of 93 NE counties, at 189 days against 200 in Richardson County and 127 in Sioux County. Its mean temperature is 50°F.
- Dodge County: April 15 to October 20 (189 days, 29 WNV)
- Saunders County: April 15 to October 20 (189 days, 14 WNV)
- Otoe County: April 16 to October 22 (189 days, 3 WNV)
- Nemaha County: April 15 to October 20 (188 days, 3 WNV)
West Nile in Washington County
From 1999 to 2025, CDC ArboNET counted 42 human West Nile cases in Washington County (13 neuroinvasive) across 14 years. The worst was 2003 with 12; the latest was 2024.
See how the dates are worked out, and reading the West Nile counts.