Sioux Falls, South Dakota – Extreme summer heat is making a strong return to the region Friday, with heat index values expected to climb as high as 108°F between 2 p.m. and 8 p.m. The National Weather Service (NWS) warns that the conditions will be hazardous across eastern South Dakota, northwest Iowa, and northeast Nebraska, increasing the risk of heat-related illnesses and putting pressure on local infrastructure.
The advisory includes major cities such as Sioux Falls, Yankton, Storm Lake, Sioux Center, Cherokee, Le Mars, and North Sioux City. Officials urge residents to limit outdoor activities, drink plenty of water, and check on vulnerable neighbors, especially seniors and those without access to cooling. Car interiors can heat to deadly levels within minutes, so children and pets should never be left unattended.
Hot pavement and road surfaces are also a concern. Transportation officials note that roadways like I-29, I-90, and Highways 75 and 20 may experience pavement buckling or vehicle breakdowns due to extreme surface temperatures. In addition, power grids in Sioux Falls and the Siouxland area could face higher demand from widespread air conditioner use.
Outdoor workers in areas such as Lyon County, Dakota County, and Clay County are advised to wear light clothing, take frequent shaded breaks, and recognize early signs of heat exhaustion—such as dizziness, weakness, or nausea.
The most dangerous period will occur from mid-afternoon to early evening Friday, when heat and humidity are expected to peak. Cooling centers are open in Sioux Falls, Yankton, and Storm Lake for those needing relief.
More advisories could follow if this heat wave extends into the weekend. Residents are encouraged to stay informed through official weather updates, use cooling resources when necessary, and take precautions to protect themselves and their communities during this period of extreme heat.
