"Rainfall overnight and into the morning hours has led to a substantial decrease in fire activity," Cal Fire said in an update on Sunday afternoon.

Rain was falling across Southern California on Sunday, bringing some relief to thousands of firefighters who have been battling multiple major wildfires in the LA area.

The rain is raising concerns about potential mudslides in recent burn scar areas, including Malibu, Altadena, and other regions.

After weeks of windy and dry weather, rain has fallen in parched Southern California and is expected to aid firefighters who are mopping up multiple wildfires. But potentially heavy downpours on charred hillsides could bring new troubles such as toxic ash runoff.