Mosquito season in Ziebach County, SD: when it starts and ends
Mosquito months in Ziebach County
In a normal year mosquito season in Ziebach County, SD starts around April 29 and ends around October 9, about 23 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Ziebach County, and when
- Start tipping out standing water weekly by April 15.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 9.
- 2 West Nile cases since 2016 (last 2024): you should use repellent at dusk July to August, more so if over 60.
Ziebach County against the rest of SD
Ziebach County has the 26th longest season of 66 SD counties, at 163 days against 179 in Yankton County and 139 in Lawrence County. Its mean temperature is 47.5°F.
- Buffalo County: April 28 to October 9 (164 days, 2 WNV)
- Hand County: April 29 to October 9 (163 days, 6 WNV)
- Mellette County: April 30 to October 10 (163 days, 4 WNV)
- Jackson County: May 1 to October 11 (163 days, 1 WNV)
West Nile in Ziebach County
From 1999 to 2025, CDC ArboNET counted 9 human West Nile cases in Ziebach County (0 neuroinvasive) across 4 years. The worst was 2003 with 4; the latest was 2024.
Background: when the season starts across the US; how the dates are worked out.