Temperatures are continuing to cool slightly Friday. The coast will be in the 70s to 80s. The interior will remain hot with some areas reaching the triple digits.
The marine layer will deepen with increased onshore flow, especially on the South Coast. Into the holiday weekend, temperatures will continue to decrease as the ridge of high pressure starts to weaken.
An excessive heat warning will stay in effect until Saturday night in the mountains and in the San Luis Obispo County valleys. Temperatures could still reach into the triple digits.
A trough will start pushing the ridge southeast on Sunday, cooling the interior further. The coast may recover slightly Sunday with less onshore flow.
As the trough moves over California through Tuesday, temperatures everywhere will cool to near or slightly below average with falling heights, an earlier sea breeze, and a deep marine layer.
By Wednesday, the trough will depart the region and temperatures will recover slightly again, reaching near normal by Thursday.