After weeks of cooler, wetter conditions, a significant shift in weather patterns is on the horizon for a large portion of the United States. A high-pressure dome is set to build over the central U.S., ushering in a period of summer-like heat that will impact approximately 150 million Americans. This unseasonably warm weather is expected to persist through the middle of next week, bringing temperatures soaring 10–15 degrees above average for this time of year.