For the second day in a row, an intense heat wave is bearing down on central and southern regions of the United States, with tens of millions of residents facing extreme heat warnings as dangerously high temperatures and oppressive humidity blanket much of the nation.
According to the National Weather Service, heat index readings — which factor in humidity to reflect how hot it actually feels — are expected to top 105 degrees Fahrenheit (40.5 Celsius) in areas stretching from Memphis to Montana to Las Vegas. In portions of the Southwest, actual air temperatures could climb as high as 120 degrees Fahrenheit (49 Celsius).
The punishing heat is being driven by what meteorologists call a heat dome, a weather phenomenon in which atmospheric pressure traps warm air near the surface, intensifying and extending already scorching temperatures.
There is little sign of relief on the horizon for most of the country. Bob Oravec, a meteorologist with the National Weather Service, said Saturday that the heat dome appears to be locked in place. “It looks like it is going to be pretty much stationary in that position as we go through the week,” he said.
Oravec noted that some easing of the heat could arrive in the central United States by next weekend, though even that potential break may not last long.
Health authorities are sounding the alarm for those most at risk, including children, elderly individuals, and people living with certain medical conditions, all of whom face a heightened danger of serious heat-related illness such as heat stroke. Experts are advising people to find air-conditioned spaces or visit a cooling center, stay well hydrated, and minimize time spent in direct sunlight.
The extreme heat comes on the heels of a troubling climate milestone: the continental United States recorded its second-hottest first half of the year ever measured in 2026, according to data tracked by the National Centers for Environmental Information.
