The National Weather Service says Southern California's sharp warming trend will build into the weekend, with above-normal temperatures in many areas.
Forecasters issued an excessive heat warning beginning at 1 p.m. Friday warning that the hottest conditions will be Friday through Sunday.
High temperatures for the lower deserts will be 115 to 120 degrees. In the Inland Empire, temperatures could reach between 105 and 112 degrees.
San Diego's coastline communities will see temperatures in the mid 80s by Friday afternoon.
The extended period of hot and dry conditions will also bring elevated fire danger.