A weak trough was expected to bring seasonally warm weather to San Diego County today through Tuesday, the National Weather Service said.
Marine layer clouds will extend as far inland as the western valleys each night before retreating back to the coast each morning, forecasters said.
High temperatures along the coast on Sunday will be 73-78 degrees with overnight lows of 59-64, the NWS said. Inland highs will be 79-84.
Highs in the western valleys will be 82-87 with overnight lows of 60- 66. Highs near the foothills will be 89-94.
Highs in the mountains will be 86-94 with overnight lows of 57-67. Desert highs will be 104-109 with overnight lows of 74-82.
Warmer weather returns Wednesday and Thursday as high pressure rebuilds over the Southwest followed by a weak trough that will bring minor cooling again next weekend, forecasters said.
"The marine layer presence will maintain itself over the coast and western valleys through early next week," the NWS said. "This will provide more clouds and patchy fog each night and morning along with moderated temperatures each afternoon. The coolest day is looking like Tuesday as the troughing pattern deepens a bit to our north."
The county will see greater onshore flow as well, which will lead to breezy afternoons and evenings across the mountains and deserts, the NWS said. West and southwest winds will gust 25-35 mph across these areas.
Elevated fire weather conditions will impact mountain areas and desert slopes through Tuesday, the weather service said.
