Emergency services spent the weekend sifting through the charred wreckage of California's deadliest ever wildfire, searching for signs of nearly 1,000 people believed still missing as crews made progress in bringing the blaze under control.

The remains of 77 people have been recovered, the Butte County Sheriff's Office said late on Sunday, as it cut the number of missing to 993 from 1,276. It gave no other details.

The Camp Fire broke out in Northern California on November 8 and quickly all but obliterated Paradise, a mountain town of nearly 27,000 people around 145 kilometres north of state capital Sacramento.

Officials said it had consumed about 150,000 acres and was 65 per cent contained late on Sunday, up from 60 per cent earlier in the day, as prospects of a heavy rainstorm from late Tuesday, local time, raised hopes that that percentage will rise as the week progresses.