It's expected to be a bit cooler in San Diego County Saturday and Sunday as onshore flow and a fairly deep marine layer prevail west of the mountains, the National Weather Service said.
Some of the cooling was predicted to be felt over the mountains and deserts as well, with gusty westerly winds through the passes in the afternoons and evenings, forecasters said.
Because of thick marine clouds, clearing may be slower Saturday near the coast, and skies may remain partly cloudy Saturday afternoon, the NWS said.
Warming was forecast to begin on Sunday over the high deserts, and then all areas Memorial Day through midweek as the marine layer thins and onshore flow weakens, the NWS said.
High temperatures in coastal areas Saturday were expected to be 66-71 degrees with overnight lows of
53-58, the NWS said. Western valley highs will be 69-74 and 73-78 in the foothills with overnight lows of 48-55.
Mountain highs were expected to be 73-83 with overnight lows of 44-51. Highs in the deserts will be 98-103 with overnight lows of 63-70 and wind gusts of up to 40 mph.
Beginning Monday, a high-pressure ridge was predicted to push first into Northern California and eventually spread into Southern California through next week, the NWS said.
"This will bring progressively warmer conditions to our area, except for the immediate coastal areas," forecasters said. "The warmest days will probably be Wednesday and Thursday, with temperatures 105-110 degrees in the lower deserts, and around 100 degrees in the Mojave Desert."
Some moisture and return flow should help to temper the excessively warm conditions, especially by next weekend, the NWS said.
