An unusual winter heatwave is expected across California this week with record temperatures in the forecast for multiple cities from the San Francisco Bay Area to Los Angeles.

In Southern California, where temperatures are predicted to be 15 to 20 degrees above normal from Wednesday morning through Sunday, the National Weather Service upgraded a heat watch to a heat advisory.

The heat watch and advisory were the first to be issued by the Los Angeles weather office in the month of February, according to records dating to 2006. Most heat watches and warnings in the area are issued from May through October.