Firefighters gain ground on Calfornia wildfire as weather conditions improve

The Mountain Fire broke out on Wednesday and quickly spread over a vast area of southern California (Ethan Swope/AP)

Firefighters in southern California have gained ground on a wildfire that has ravaged more than 100 structures as gusty winds subsided.

Evacuation orders have been downgraded to warnings for residents in several areas of Ventura County, where the Mountain Fire held at around 32 square miles and was 21% contained, authorities said.