Extreme heat warnings cover at least 40 million across the central and southern U.S.

What happened

At least 40 million people were under extreme heat warnings across central and southern parts of the United States on Sunday, the Associated Press reported. Heat and humidity pushed heat-index values above 105 degrees Fahrenheit from Minnesota to Mississippi, while Rapid City, South Dakota, reported an all-time high of 112 degrees on Saturday. Meteorologists attributed the prolonged conditions to another heat dome trapping hot air over the region.

Why it matters

Long-duration heat raises the risk of illness and death while straining workers, power systems, transportation, agriculture, and households without reliable cooling. The most effective response combines clear alerts, cooling centers, hydration, workplace protections, neighbor check-ins, resilient buildings, and longer-term emissions reductions.

What to watch

• Overnight temperatures, heat-index forecasts, and whether warnings expand or persist into the workweek.
• Emergency-room demand, cooling-center access, grid reliability, and protections for outdoor workers.
• Local plans for shade, trees, efficient cooling, backup power, and outreach to people living alone.

Sources & evidence

• Sweltering heat wave grips central and southern US for a second straight dayAssociated Press report published July 26, 2026, on extreme heat warnings, heat-index conditions, and the Rapid City temperature record.

Topics

• Extreme Heat
• Heat Dome
• Public Health
• Cooling Centers
• United States