Maps show heat alerts as extreme temperatures threaten millions

Key Points:

• Approximately 100 million people across the U.S. are experiencing extreme heat as a heat dome spreads from the West to the Northeast, with temperatures reaching record highs, such as 111°F in Billings, Montana, and 109°F in Salt Lake City, Utah.
• The heat wave is causing temperatures 20 to 30 degrees above average, with heat indices reaching into the high 90s to over 100°F, and is expected to peak in the Northern Tier on Tuesday and the Northeast on Wednesday.
• The prolonged and exceptionally rare heat increases risks of heat-related illnesses, wildfires, and limited overnight cooling, with wildfires actively burning in California and Colorado, prompting evacuation orders and calls for increased firefighting funding.
• In contrast, parts of the South are experiencing heavy rain and flooding, including historic flash floods in Missouri that required airlifting over 200 people, and significant rainfall in New Orleans causing knee-high water.
• Forecasters warn that the heat dome will persist through next weekend, maintaining hazardous conditions across a wide region, while the combination of heat and dry conditions continues to fuel wildfire threats.