Mosquito season in Brown County, MN: when it starts and ends
Mosquito months in Brown County
In a normal year mosquito season in Brown County, MN starts around April 26 and ends around October 11, 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 12.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 11.
- 1 West Nile case since 2016 (last 2016): you should use repellent at dusk July to July, more so if over 60.
Brown County against the rest of MN
Brown County has the 10th longest season of 87 MN counties, at 168 days against 176 in Winona County and 118 in Cook County. Its mean temperature is 44.9°F.
- Hennepin County: April 25 to October 11 (169 days, 67 WNV)
- Watonwan County: April 26 to October 12 (169 days, 2 WNV)
- Houston County: April 27 to October 12 (168 days, 1 WNV)
- Dakota County: April 26 to October 11 (167 days, 26 WNV)
West Nile in Brown County
From 1999 to 2025, CDC ArboNET counted 12 human West Nile cases in Brown County (3 neuroinvasive) across 5 years. The worst was 2012 with 4; the latest was 2016.
More: how the dates are worked out · when the season starts across the US.