A ridge of high pressure was predicted to dominate Sunday's weather in San Diego County, continuing seasonably hot conditions inland with mild conditions near the coast because of the marine layer, the National Weather Service said.
Monsoonal moisture was expected to increase on Wednesday, leading to a slight chance of afternoon thunderstorms over the mountains, a condition that will continue through Friday, the NWS said.
Warming was forecast west of the mountains later in the week.
High temperatures along the coast Sunday were predicted to be 72 to 77 degrees with overnight lows of 59 to 64. Highs in the western valleys were expected to be 82 to 87, and 91 to 96 near the foothills with overnight lows of 60 to 66. Highs in the mountains were expected to be 90 to 98 with overnight lows of 62 to 71, and highs in the deserts were predicted to be 110 to 115 with overnight lows of 80 to 88.
The National Weather Service also pointed out that July 10th seems to have a pattern of hot days when looking back on the history of weather: