Mosquito season in Dakota County, MN: when it starts and ends

Mosquito months in Dakota County

In a normal year mosquito season in Dakota County, MN starts around April 26 and ends around October 11, about 24 weeks.

1. Jan
2. Feb
3. Mar
4. Apr
5. May
6. Jun
7. Jul
8. Aug
9. Sep
10. Oct
11. Nov
12. Dec

What to do in Dakota 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.
• 26 West Nile cases since 2016: you should wear EPA-registered repellent at dusk July to July, and check MN spray notices.

Dakota County against the rest of MN

Dakota County has the 12th longest season of 87 MN counties, at 167 days against 176 in Winona County and 118 in Cook County. Its mean temperature is 44.7°F.

• Brown County: April 26 to October 11 (168 days, 1 WNV)
• Houston County: April 27 to October 12 (168 days, 1 WNV)
• Freeborn County: April 26 to October 11 (167 days, 1 WNV)
• Nicollet County: April 26 to October 11 (167 days, 2 WNV)

West Nile in Dakota County

From 1999 to 2025, CDC ArboNET counted 46 human West Nile cases in Dakota County (29 neuroinvasive) across 17 years. The worst was 2025 with 8; the latest was 2025.

See how the dates are worked out, and reading the West Nile counts.