A heat wave is hitting Southern California, and temperatures will be as much as 20 degrees above normal through Thursday.

Southern California is baking under a powerful heat wave this week, prompting urgent warnings for more than 8 million people to limit time outdoors and stay cool. The National Weather Service (NWS) extended its heat advisory through 9 p.

Much of Southern California has been placed under a heat advisory on Tuesday as the first day of a four-day heat wave arrives. A ridge of high pressure will result in an extended period of hot weather this week,

Southern California will give way to sunny skies and rising temperatures this week, forecasters said. A prolonged heat wave will take hold starting Monday.