Overview

• More than 165 million people from Nebraska to New Hampshire and Florida are under heat advisories or extreme heat warnings with heat indices reaching 116°F.
• PJM Interconnection LLC issued hot weather alerts across its entire 13-state grid and warned it may curtail power exports if soaring demand threatens stability.
• Severe thunderstorms in the Midwest produced wind gusts over 90 mph in Spencer, Iowa and a confirmed tornado in Dixon, South Dakota, leaving over 170,000 customers in four states without power.
• Air quality along the I-95 corridor is unhealthy for sensitive groups as heat-trapped pollution merges with Canadian wildfire smoke to worsen haze.
• A cold front later this week is expected to erode the heat dome, easing temperatures for much of the nation but prolonging high humidity in the deep South.