Temperatures rose quickly on Thursday and reached highs of 90 in a few coastal areas, and a high of 86 degrees was recorded at Lindbergh Field, according to the National Weather Service.
Weather service Meteorologist Michael Watkins said that high pressure over the desert areas and the recent Santa Ana winds caused the temporary heat wave. But that high pressure that led to temperatures of up to 10 degrees above average has begun to weaken.
Onshore flow and low clouds along the coast was also expected to bring gradual cooling next week. However, Watkins said moisture levels would remain low for the next seven days.
In coastal San Diego County and in the valleys, highs were forecast to decrease from the mid-70s on Sunday to around 70 on Friday, and highs of up to 79 degrees in the mountains will also lower to around 70, according to the NWS.
Highs in the deserts in the low 80s were expected to fall to around 77 degrees next week.