If you've got outdoor plans across eastern South Dakota, Southwest Minnesota, or Northwest Iowa this weekend, get ready for some serious summer heat. The National Weather Service in Sioux Falls is forecasting hot and humid conditions that will settle into the region through the weekend. NWS Sioux Falls NWS Sioux FallsHeat index values could reach around +105 degrees in some locations during the hottest part of the day. Be sure to check in on neighbors, family members, and friends who may not have access to air conditioning. If you're heading to area lakes, ballgames, festivals, or backyard barbecues, remember that the sun is strongest during the afternoon hours.