The first few days of summer, which began Sunday, will feature high heat and potent thunderstorms across large swaths of the country, forecasters say.

Millions of Americans could soon face dangerous and potentially life-threatening conditions as a heat wave descends on the U.S.

Heat builds across the Northeast early next week, peaking Tuesday into Wednesday before a cold front brings relief by Thursday. Maps show forecast temperatures near you. NOAA graphical maps show how hot temperatures will reach in the U.S. Sunday, May 17 ...

A widespread heat wave is building across the United States, and when the temperature is rising, how you eat, drink and exercise can all have an effect on your health.

A widespread heat wave is pushing dangerously high temperatures across large parts of the United States this week.