Mosquito season in Pierce County, NE: when it starts and ends
Mosquito months in Pierce County
In a normal year mosquito season in Pierce County, NE starts around April 21 and ends around October 16, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Pierce County, and when
- Start tipping out standing water weekly by April 7.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 16.
- 4 West Nile cases since 2016 (last 2025): you should use repellent at dusk June to August, more so if over 60.
Pierce County against the rest of NE
Pierce County has the 50th longest season of 93 NE counties, at 178 days against 200 in Richardson County and 127 in Sioux County. Its mean temperature is 48.1°F.
- Sherman County: April 21 to October 17 (179 days, 2 WNV)
- Nance County: April 20 to October 15 (178 days, 4 WNV)
- Thurston County: April 21 to October 16 (178 days, 2 WNV)
- Wayne County: April 21 to October 16 (178 days, 3 WNV)
West Nile in Pierce County
From 1999 to 2025, CDC ArboNET counted 17 human West Nile cases in Pierce County (8 neuroinvasive) across 8 years. The worst was 2003 with 7; the latest was 2025.
Background: reading the West Nile counts; how the dates are worked out.