Sioux Falls, S.D. – Dangerously high temperatures will blanket much of South Dakota through Friday, with parts of the James River Valley expected to hit 100°F by Thursday, just as July 4th festivities ramp up.
According to the National Weather Service in Sioux Falls, a Major Heat Risk is in place from Huron to Mitchell to Yankton, especially in areas west of the James River Valley. Daily highs will reach 89–100°F, with “feels-like” temperatures potentially even higher due to increased humidity.
Cities like Mitchell and Yankton are expected to see the most intense heat, where outdoor exposure between 10 a.m. and 6 p.m. poses the greatest risk. Health officials urge residents to stay hydrated, wear light clothing, limit outdoor time, and check on elderly neighbors, children, and pets — all more vulnerable to heat-related illness.
This heat wave could challenge power grids and affect Independence Day events. Emergency crews advise keeping phones charged, using fans or air conditioning, and watching for signs of heat exhaustion.
Heat alerts remain in effect through Friday, July 4, with updates expected if the pattern intensifies.
