A wildfire sparked Sunday afternoon in Clearlake has spread to about 100 acres within an hour, triggering two evacuation orders, according to fire officials.

A nearly 40,000-acre wildfire forced people from their homes in two Southern California counties over the weekend as firefighters worked to contain the blaze in challenging terrain.

Learn about the 23,000-acre wildfire in south-central California, its impact on Santa Barbara and San Luis Obispo counties, and the ongoing firefighting efforts as dry conditions and warm weather fuel the blaze.