Many areas reached or topped 100 degrees and even beach cities saw highs in the 80s and 90s. And a number of new records for October 12 were set in several SoCal cities, including Long Beach (at 102, beating its previous record of 96), Santa Ana (at 105, beating its previous record of 104) and Fullerton (at 101, beating its previous record of 99).
Wednesday's high temperature in downtown Los Angeles was 99 degrees, tying a record set for the date in 1950. The high was 20 degrees above normal.
Meteorologists says the heat-up is being caused by combination of an upper-level high-pressure system and offshore flow of air that keeps the normal cooling ocean air at bay.
The scorching heat was expected to persist into Thursday, with temperatures dropping Friday for the weekend.
Some gusty winds tagged along with the heat for some SoCal areas, flaring up concerns about wildfires.
A brush fire broke out in the Santa Ana River Bed in the afternoon, burning at least 10 acres. Flames jumped 40 to 50 feet in the air and thick, black smoke rose out of the heavy brush down below.
Cal Fire urges residents to be careful over the next couple days. Even though last week's rainfall helped, a lot of the brush throughout the Inland Empire is still very dry.
"With the Santa Ana wind event, all that moisture that was collected and all those lighter fuels will dissipate. It will all be gone, and it will be as though it never rained at all," said Capt. Mike Smith.
It's been a mild fire season, but officials said firefighters are ready for the dangerous conditions.
Some residents also said they're prepared for the worst.
"We have all the important papers. We keep it in one place. If the fire comes in, we'll put it in one of the cars," said Porter Ranch resident Sunil Patel.
Patel said his family also has water bottles, a first aid kit and insurance papers ready.