High temperatures were predicted to be slightly lower Wednesday in San Diego County, with the marine layer deepening to around 2,500 feet, the National Weather Service said.
Coastal low clouds were more extensive early Wednesday than recent nights, covering much of the valleys.
Along the coast Wednesday, it was expected to be mostly sunny with high temperatures from 69 to 74 degrees, the NWS said. The western valleys were expected to be mostly sunny with highs from 72 to 76 and near the foothills from 76 to 81. It should be mostly sunny in the mountains with highs from 75 to 85. The deserts were expected to be mostly sunny with highs from 100 to 104.
High pressure over central and southern California should bring a warming trend into the weekend with greater warming for inland areas, forecasters said.
The heat could peak over the weekend with high temperatures for the deserts around 10 degrees above average. High pressure was likely to then weaken with a gradual cooling trend into the middle of next week.
The highest heat risk was expected over the weekend in the deserts with areas of risk for major impacts and extreme impacts in the lower deserts.
High pressure was predicted to begin to weaken early next week as a weak trough of low pressure develops somewhere near the coast of northern and central California.
