Strong high pressure over the eastern Pacific and weak offshore flow was expected to bring much warmer weather Wednesday through Friday in San Diego County, the National Weather Service said.
Highs Thursday are forecast to be 79 to 84 near the coast, 88 to 92 inland, 91 to 96 in the western valleys, 79 to 88 in the mountains and 95 to 98 in the deserts, according to meteorologists.
Onshore flow may return near the coast on Saturday and spread cooling inland through early next week with high temperatures for the coast and valleys returning to around average for Tuesday.
Night and morning coastal low clouds and fog were expected to increase in coverage by Sunday and Monday, the NWS said.
A weak trough of low pressure off the Southern California coast for the weekend may draw some tropical moisture northward, forecasters said. Weak onshore flow and a weak coastal eddy were likely to begin to bring some cooling near the coast on Saturday with that cooling gradually spreading inland through early next week.
High temperatures for the coast and valleys would return to around average on Tuesday with high temperatures for the lower deserts only falling slightly into the upper 90s, the NWS said.
Night and morning coastal low clouds and fog may increase in coverage by Sunday and Monday and spread a little farther inland, possibly into the far western valleys, for early next week.
City News Service contributed to this article.