An extreme heatwave is forecasted to hit Southern California, with temperatures expected to range between 105°F (40.5°C) and 110°F (43°C) in the Coachella Valley, and upwards of 95°F (35°C) in the San Joaquin Valley. More than 18 million people are under warnings for extreme temperatures, as officials advise residents to limit outdoor activities during the hottest parts of the day.