A late season heatwave will build in the Plains this week and eventually will expand into the eastern part of the country by next week. For many, this will be a prolonged period of dry and hot weather that will last for at least 10 days. The Plains will see highs in the 100s and that area of upper 90s and 100s will expand into the Ohio and Tennessee Valleys over the weekend into early next week. The I-95 corridor will also see highs in the upper 90s and 100s early next week. It will take a cold front to break the heat later next week.