A hot weather advisory has been issued for inland areas through next week.
High pressure will bring hot weather to the deserts, lower mountain slopes and inland valleys.
Temperatures of "around 110 degrees" are forecast in the lower deserts, "around 100 degrees" in the upper deserts, and in the 90s on the lower mountain slopes and in the inland valleys are expected through Monday.
Temperatures are estimated to reach 5 to 10 degrees above average in these areas.
A persistent marine layer will keep coastal areas cooler and cloudier with high temperatures a few degrees below average.
Those in the hotter areas are advised to avoid strenuous outdoor activity if possible. Those that have to be outside in the heat are advised to drink plenty of non-alcoholic, non-caffeinated fluids, wear lightweight loose-fitting clothing, a hat, and use sunscreen.
Children and/or pets should never be left in enclosed vehicles, even briefly.
Experts say this weather could be deadly for unprepared campers or hikers.