Wednesday was a warm day away from the coast with Paso Robles almost hitting 90 and coastal valleys in the mid to upper 70s, definitely not extreme in terms of highs but warmer than average.
We'll get another very similar day on Thursday before temps slowly leak thru the weekend. Early next week temps take a more significant dive.
There will be some changes developing tonight. The marine clouds which have taken a few days off for most (outside the Southcoast) look to return. This will drive beach temps and the near coastal valleys down a few degrees with the night and morning clouds limited to the beachline.
The larger changes take place due to the larger weather pattern.
A short-wave ridge (a transitional ridge in the upper atmosphere) moves out early Thursday as the jet stream flattens and becomes more west-to-east (zonal). Temps will drop a few degrees by day thru the weekend.
A much larger trough digs out in The West early next week and temperatures by Tuesday could differ up to 20 degrees compared to tomorrow's highs inland.
The coastal trend is down as well just not as dramatically into early next week. After temps bottom out on Tuesday, the rest of next week should see temps steadily rise as a ridge of high pressure ultimately replaces the strong-cool trough.