Low pressure over California was expected to weaken early this week with high pressure to the east expanding across the area through the weekend, the National Weather Service said.
A warming trend should continue through the weekend with high temperatures peaking around Sunday at 5 to 10 degrees above average, forecasters said.
The marine layer may decrease in depth with night and morning low clouds becoming patchier and limited mostly to coastal areas by the weekend.
Along the coast Wednesday, it was expected to be 71 to 76 degrees, 76 to 79 inland, 77 to 81 in the western valleys, 81 to 86 near the foothills, 79 to 88 in the mountains and highs around 100 in the deserts, the NWS said.
High pressure to the east was predicted to continue to move slowly westward and be centered over northwest Mexico on Sunday, then begin to weaken early next week.
The heat risk for next weekend could be near thresholds for an excessive heat warning for the lower deserts, and for heat advisories for the valleys, lower elevations of the mountains, and inland coastal areas.
City News Service contributed to this article.