Mosquito season in Hyde County, SD: when it starts and ends

Mosquito months in Hyde County

In a normal year mosquito season in Hyde County, SD starts around May 2 and ends around October 10, about 23 weeks.

What to do in Hyde County, and when

Start tipping out standing water weekly by April 18.
Book any yard treatment for early May, ahead of the July peak.
Repellent can go away after October 10.
1 West Nile case since 2016 (last 2018): you should use repellent at dusk July to August, more so if over 60.

Hyde County against the rest of SD

Hyde County has the 35th longest season of 66 SD counties, at 161 days against 179 in Yankton County and 139 in Lawrence County. Its mean temperature is 45.8°F.

Perkins County: May 1 to October 9 (161 days, 1 WNV)
Bennett County: May 2 to October 10 (161 days, 1 WNV)
Corson County: April 30 to October 7 (160 days, 3 WNV)
Dewey County: April 30 to October 7 (160 days, 11 WNV)

West Nile in Hyde County

From 1999 to 2025, CDC ArboNET counted 9 human West Nile cases in Hyde County (1 neuroinvasive) across 4 years. The worst was 2003 with 5; the latest was 2018.

See how the dates are worked out, and when the season starts across the US.