A long-duration heat wave is taking shape over the western half of the U.S. and forecast to stick around in the days ahead.

Parts of California and Arizona are under extreme heat warnings again Saturday while sweltering summerlike weather stretched as far north as Nebraska — just a day into spring.

Unusual March heat has pushed temperatures into record territory in parts of the West. More extremes are expected in the days ...

Forecasters are calling the early heat event 'unprecedented,' with temperatures as high as 25 degrees above normal in some ...

The prolonged heat wave is expected to peak on Tuesday and remain until Friday for most areas across the region.

Phoenix has seen several days with temperatures topping 100 degrees, and more extreme heat is expected through the weekend.