Sioux Falls, SD – A mix of dense fog and extreme heat is creating hazardous travel and health conditions across eastern South Dakota, northwest Iowa, and southwest Minnesota through Sunday evening.
According to the National Weather Service in Sioux Falls, a Dense Fog Advisory is in effect until 9 a.m. Saturday, followed immediately by an Extreme Heat Watch stretching into Sunday evening. Heat index values may top 108°F, especially west of the James River, while visibility early Saturday dipped below a quarter mile in multiple counties.
Drivers in Sioux Falls, Brookings, Vermillion, and along I-29 and I-90 are urged to slow down, use headlights, and allow extra distance between vehicles. The combination of poor visibility and rising temperatures could lead to delays and dangerous road conditions.
The heat is expected to intensify throughout Saturday and Sunday, particularly in Yankton, Spencer, Sheldon, and Rock Rapids. Residents should avoid strenuous activity outdoors, drink fluids regularly, and never leave children or pets in parked vehicles.
Humidity will keep nighttime temperatures high, with little relief expected until early next week. Low storm chances remain possible late Sunday into Monday.
Warnings remain in effect across the tri-state area through Sunday. Further advisories may be issued.
📅 Five-Day Weather Outlook (Sioux Falls, SD):
- Saturday: AM fog, hot and humid. High 97°F. Heat index up to 106°F.
- Sunday: Mostly sunny, extreme heat. High 99°F. Storm chance late.
- Monday: Isolated PM storms, hot. High 94°F.
- Tuesday: Cooler, scattered storms. High 85°F.
- Wednesday: Mostly sunny and breezy. High 82°F.
