Warm conditions inland Sunday will continue before a widespread cooling for the first half of the week, the National Weather Service office in San Diego said.
Marine layer low clouds and fog will continue to be present for the foreseeable future in the coast and valleys.
Monday’s high temperatures were expected to be 65 to 68 along the coast, 68 to 73 in the valleys, 69 to 79 in the mountains and 96 to 99 in the deserts, according to NWS.
The weather agency predicts a trough of low pressure will position itself near Central/Southern California through midweek. The increased onshore flow will deepen the marine layer, bring gusty west winds to the mountains and desert slopes and cooler conditions.
There is a slight chance for some convective showers to develop over the mountains and high deserts and patchy drizzle possible over the coastal basin.
Highs for inland locations are expected to take a nose-dive with Tuesday to be the coolest day of the week. Highs are forecast 10 to 15 degrees below average away from the coast on Tuesday.
As the low pressure system moves east for the second half of the week, temperatures will slowly moderate, but below average temperatures are expected to continue into next weekend.