Heat Advisories are in effect across a wide band of the Northern Plains through Thursday evening, as a persistent heat dome keeps temperatures and heat index values pushing toward 100°F from the Black Hills of South Dakota to the Red River Valley of Minnesota and North Dakota — with the NWS Twin Cities warning that ongoing heat events build cumulative danger over time.
Minnesota: Extreme Heat Warning Now, Heat Advisory Through Thursday
The NWS Twin Cities office has issued an Extreme Heat Warning through 9 PM CDT Wednesday for central, south-central, southwest and west-central Minnesota and west-central Wisconsin — covering St. Cloud, Mankato, Willmar, Morris, New Ulm, Redwood Falls, Montevideo and the Eau Claire, WI metro. Heat index values up to 100°F are expected this afternoon.
The warning transitions to a Heat Advisory from 9 PM tonight through 9 PM Thursday for the same counties, with heat index values up to 95°F continuing. The Twin Cities office offered an important medical context: “Cumulative heat stress significantly increases the risk of heat exhaustion and heat stroke as time goes on.” A multi-day event like this one compounds the risk for anyone who cannot adequately cool down overnight.
South Dakota: Black Hills, Pierre and the Missouri River Country
The NWS Rapid City office has a Heat Advisory through 9 PM MDT Thursday for a sweeping zone across western, southwestern and south-central South Dakota and northeast Wyoming. Heat index values of 95 to 105°F are forecast for Rapid City, Sturgis, Spearfish, Belle Fourche, Pine Ridge, Hot Springs, Kadoka, Wall, Midland, Philip, Winner, Mission and Rosebud — as well as Devil’s Tower and Gillette in Wyoming.
The Black Hills’ popular summer destinations — Sturgis (home of the motorcycle rally in early August), the Badlands, Mount Rushmore and Custer State Park — are all within or near the advisory zone. Visitors to these high-traffic outdoor attractions should plan outdoor activities for the early morning and late evening hours.
The NWS Aberdeen office issued separate advisories for central South Dakota (Pierre, Fort Pierre, Murdo, Highmore, Gettysburg, Mobridge) with heat index values up to 100°F, and for northeast South Dakota and west-central Minnesota (Aberdeen, Watertown, Milbank, Sisseton, Ortonville, Wheaton) with heat index values up to 95°F, both through 10 PM CDT Thursday.
North Dakota: Bismarck and the Southern Tier at Near 100°F
The NWS Bismarck office has a Heat Advisory through 10 PM CDT Thursday for southern North Dakota — covering Bismarck, Mandan, Dickinson, Jamestown, Washburn, Watford City, Medora, Hettinger, Bowman, Fort Yates and the full Missouri River corridor. Heat index values and temperatures are expected near 100°F Wednesday afternoon.
The Fargo-Moorhead metro and southeast North Dakota plus west-central Minnesota are under a separate Heat Advisory from the NWS Grand Forks office, with heat index values up to 99°F through Thursday night — covering Fargo, Moorhead, Valley City, Wahpeton, Fergus Falls and the Red River Valley.
Staying Safe Through Thursday
All NWS offices advise staying in air-conditioned spaces during peak afternoon hours, drinking water before feeling thirsty, wearing lightweight and loose-fitting clothing, and checking on elderly neighbors daily. Heat stroke is a 911 emergency. Outdoor workers should schedule frequent rest breaks in shade or air conditioning throughout the day.
