Cooler conditions in San Diego County were forecast for Sunday with night and morning low clouds and fog continuing at the coast and in portions of the western valleys, the National Weather Service said.
Breezy conditions were expected through the passes, mountains and the deserts Sunday.
Low clouds were continuing to scatter at 9 a.m. in the inland valleys, and Sunday has potential for more widespread clearing at the beaches, forecasters said.
High temperatures along the coast Sunday were predicted to be 67 to 72 degrees with overnight lows of 51 to 56. Highs in the western valleys were expected to be around 71, and 71-76 near the foothills with overnight lows of 49 to 54. Highs in the mountains were expected to be 71 to 81 with overnight lows of 44 to 53, and highs in the deserts were predicted to be 94 to 99 with overnight lows of 62 to 71.
A ridge of high pressure may start to move east from the Pacific, replacing the trough of low pressure that has been bringing cooler, cloudier and breezy conditions. This ridge could support a warming trend through Wednesday or Thursday.
The warmest days of the week were expected to be Wednesday west of the mountains and in the high desert and Thursday in the low desert.
During the peak of the heat, the coast was predicted to be in the 70s, the inland valleys in the 80s, the high desert in the mid-90s, and the low deserts at 102 to 107 degrees. Night and morning low cloud coverage could become more confined to coastal areas and portions of the western valleys for the majority of the work week.
By Friday, the ridge was expected to move east. There could be some degree of cooling, increase in cloud coverage, and increase in westerly winds in the mountains and deserts next weekend.
No hazardous marine conditions were expected through Thursday.