Upper Sioux Agency State Park Weather Forecast
- 61
- 81
Slight Chance Thunderstorms
- 56
- 78
Mostly Sunny
- 61
- 82
Chance Rain Showers
- 56
- 78
Chance Thunderstorms
- 54
- 74
Slight Chance Thunderstorms
- 57
- 76
Partly Sunny
Today 15 Aug Yellow Medicine
Mostly cloudy. Areas of fog in the morning. Slight chance of Thunderstorms early in the morning. Slight chance of Thunderstorms early in the Afternoon, then chance of Thunderstorms late in the afternoon. Highs in the lower 80s. South Winds 5 to 10 Mph shifting to the west in the afternoon. Chance of Thunderstorms 50 percent.
Tonight 15 Aug Yellow Medicine
Mostly cloudy with a 20 percent chance of Thunderstorms in the Evening, then partly cloudy after midnight. Lows in the lower 60s. Northwest Winds 5 to 10 Mph.
Upper Sioux Agency State Park Temperature Statistics
August Temperature
Granite Falls, Granite Falls Municipal Airport/Lenzen-Roe Memorial Field (5.6 miles)
Lowest 5 August, 2026
50.5 °FAverage August
72 °FHighest 12 August, 2026
85.3 °F
Climate (2021–2026)
Granite Falls, Granite Falls Municipal Airport/Lenzen-Roe Memorial Field (5.6 miles)
Average Low 2021–2026
37.4 °FAverage 2021–2026
48 °FAverage High 2021–2026
58.5 °F