35,000-acre wildfire in San Luis Obispo County is currently the largest in California

Firefighters in San Luis Obispo County are battling what is currently the largest wildfire in California so far this year.

The so-called Madre Fire broke out Wednesday afternoon in a rural area off Highway 166, east of Sycamore Creek. It quickly exploded to more than 35,000 acres, according to CalFire.

Overnight, fire crews managed to get 5% containment.

Evacuation orders and warnings have been issued for areas in San Luis Obispo and Santa Barbara County.

The cause of the fire is not known.