The fires are burning in Riverside County, and firefighters have attacked the flames with both ground and air resources.
The largest of the three blazes is known as the Rabbit Fire, which CAL FIRE said exploded in size to more than 7,000 acres within 24 hours. As of Monday, the fire stretched to 7,600 acres. Firefighters gained some ground on the blaze, increasing containment to 35% through the night into Monday.
Evacuation warnings are in place south of Seneca Springs and south of East 1st Street.
Firefighters said they had difficulty containing the blaze because of its rapid movement.
According to ALERTCalifornia, crews worked to protect important infrastructure on Mount Davis on Saturday.
Prior to the Rabbit Fire, the Reche Fire broke out a little before 1 p.m. Friday. The Reche Fire prompted evacuation orders before they were all eventually lifted. The blaze is nearly contained after burning more than 430 acres.
About two hours later, the Highland Fire broke out in the Beaumont area, prompting evacuations before they were eventually pulled back. The Highland Fire consumed more than 100 acres and is almost fully contained.
On Saturday, the Riverside Fire Department responded to another fire near Gavilan Road and Smith Road around 3:30 p.m., prompting several road closures and evacuations near Perris.
The Gavilan Fire grew to more than 330 acres and is 50% contained.
Officials have not released the causes of the fires for all four incidents.
The fires come as millions of Americans face dangerously high temperatures this week while a powerful heat wave stretches from California to Florida. While the heat likely peaked over the weekend, it won't be going anywhere soon.
Excessive Heat Warnings are in effect for most of Southern California through Tuesday evening, including the Los Angeles area.