Mosquito season in Hutchinson County, SD: when it starts and ends
Mosquito months in Hutchinson County
In a normal year mosquito season in Hutchinson County, SD starts around April 22 and ends around October 13, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Hutchinson County, and when
- Start tipping out standing water weekly by April 8.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 13.
- 18 West Nile cases since 2016: you should wear EPA-registered repellent at dusk July to August, and check SD spray notices.
Hutchinson County against the rest of SD
Hutchinson County has the 6th longest season of 66 SD counties, at 174 days against 179 in Yankton County and 139 in Lawrence County. Its mean temperature is 47.3°F.
- Charles Mix County: April 22 to October 17 (178 days, 18 WNV)
- Union County: April 22 to October 15 (176 days, 13 WNV)
- Turner County: April 22 to October 13 (174 days, 5 WNV)
- Davison County: April 23 to October 14 (174 days, 14 WNV)
West Nile in Hutchinson County
From 1999 to 2025, CDC ArboNET counted 41 human West Nile cases in Hutchinson County (16 neuroinvasive) across 16 years. The worst was 2003 with 7; the latest was 2025.
Background: reading the West Nile counts; how the dates are worked out.