The mercury will remain near triple digits in many San Diego County areas Monday, but temperatures will begin cooling on Tuesday and keep dropping through this weekend, according to the National Weather Service.
An area of high pressure will remain over the southwestern United States Monday, then a low-pressure system will arrive on Tuesday and bring cooling through Wednesday, forecasters said. On Thursday, a low-pressure trough currently over Alaska will arrive and drop temperatures to around seasonal averages by this weekend.
High temperatures Monday are forecast to reach 89 degrees near the coast, 97 inland, 99 in the western valleys, 94 in the mountains and 108 in the deserts.
Highs will drop to the low-to-mid 90s in the western valleys on Tuesday, then fall to the low-to-mid 80s on Thursday, forecasters said. Highs in the deserts are expected to reach 107 on Tuesday but will drop to the mid-to-high 90s on Friday.
