Mosquito season in Brown County, NE: when it starts and ends
Mosquito months in Brown County
In a normal year mosquito season in Brown County, NE starts around April 27 and ends around October 13, about 24 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Brown County, and when
- Start tipping out standing water weekly by April 13.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 13.
- 1 West Nile case since 2016 (last 2025): you should use repellent at dusk July to August, more so if over 60.
Brown County against the rest of NE
Brown County has the 71st longest season of 93 NE counties, at 169 days against 200 in Richardson County and 127 in Sioux County. Its mean temperature is 50.5°F.
- Furnas County: April 26 to October 12 (169 days, 3 WNV)
- Logan County: April 26 to October 12 (169 days, 1 WNV)
- Cheyenne County: April 27 to October 13 (169 days, 11 WNV)
- Rock County: April 26 to October 11 (168 days, 0 WNV)
West Nile in Brown County
From 1999 to 2025, CDC ArboNET counted 36 human West Nile cases in Brown County (7 neuroinvasive) across 9 years. The worst was 2003 with 15; the latest was 2025.
More: how the dates are worked out · when the season starts across the US.