More storms are expected in the next couple of days - and that could prove a mixed blessing, he said.
"Light rains are good, heavy rains create mud flows," Beyer said. "Thunderstorms obviously have lightning with them. That's always a safety concern when you have people up on those exposed ridges."
Crews also must watch out for possible falling burnt trees, he said.
Some 6,000 people fled the idyllic little towns that dot the San Jacinto Mountains between Palm Springs and Hemet after the fire broke out July 15 and quickly raged across the heavily wooded area. Twenty-three structures, including the seven homes, were destroyed. There were no reports of injuries.
Authorities have said the fire was human-caused but wouldn't say whether it was accidental or intentional.
Full containment is expected on Wednesday.