An extended heat wave begins today that will continue for several days across south central Iowa. According to the National Weather Service, afternoon high temperatures are expected to reach the mid-to-upper 90s, with topping 100 degrees a possibility in many communities. An excessive heat warning will continue until Thursday evening. Heat index values will range from 105 to 110 degrees daily during peak heating hours through Thursday. Overnight lows will stay in the 70s, providing little relief. Those with outdoor plans should consider delaying them, if possible, and avoid extended activities, especially in the afternoon and early evening. Some record high temperatures are a possibility on Wednesday and Thursday. This heat wave is expected to impact many activities and continue through the first few days of school. Stay tuned to KNIA/KRLS for cancellations and delays.