Death toll rises to 81 as rescuers ramp up efforts to locate 870 missing before expected adverse weather hits.

The search for remains of victims of the devastating Northern California wildfires has taken on new urgency as rain in the forecast could complicate those efforts, while also bringing relief to firefighters on the front lines.

Hundreds of rescue workers sifted through charred rubble on Tuesday, searching for signs of the nearly 870 people listed as missing, almost two weeks after flames roared through the town of Paradise and surrounding communities.

The death toll from the wildfires in northern California has risen to 81 after two more bodies were found on Tuesday, a state report said, while thousands have been left homeless from the deadliest blaze to hit the US state.

The Camp Fire, which has burned nearly 616 square kilometres and destroyed around 13,000 homes since erupting on November 8, is 75 percent contained.

Sheriff Kory Honea said it was within the “realm of possibility” that officials would never know the exact death toll from the fires.

“As much as I wish that we could get through all of this before the rains come, I don’t know if that’s possible,” Honea said.

US President Donald Trump said ‘it’s like total devastation’ on a visit to Paradise [Evan Vucci/AP Photo]

Rain is forecast for the area this week, potentially helping douse the flames, but raising the risk of floods and mudslides that will swell the misery of 46,000 people under evacuation orders.

As much as 15cm of rain is expected to fall over several days starting early on Wednesday around the town of Paradise, a community of nearly 27,000 people, many of them retirees, that was largely obliterated by the Camp Fire.

“The task is arduous,” said Rick Crawford of the California Department of Forestry and Fire Protection. “And the possibility exists that some people may never be found.”

US President Donald Trump surveyed the remains of Paradise during a visit on Saturday. He also assessed the damage from another fire further south in Malibu, where three people died.

‘Rise from the ashes’

On Sunday afternoon, more than 50 people gathered at a memorial for the victims at First Christian Church in Chico, where a banner on the altar read, “We will rise from the ashes.”

People hugged and shed tears as Pastor Jesse Kearns recited a prayer for first firefighters, rescuers and search teams: “We ask for continued strength as they are growing weary right now.”

Paul Stavish, who retired three months ago from a Silicon Valley computer job and moved to Paradise, placed a battery-powered votive candle on the altar as a woman played piano and sang “Amazing Grace”.

More than 50 people gathered at the memorial for the victims of the wildfires in Chico, California [Noah Berger/AP Photo]

Stavish, his wife and three dogs managed to escape the fire, but their home is gone. He said he was thinking of the dead and also mourning the tight-knit community.

“This is not just a few houses getting burned,” he said. “The whole town is gone.”

Rain is forecast for midweek in the Paradise area.

The National Weather Service said the area could get 32 kilometres per hour sustained winds and 64km/h gusts, which could make it hard for crews to keep making progress against the blaze.

Focus turns to health

Reporting from a shelter in Chico, Al Jazeera’s Kristen Saloomey said that community volunteers were assisting with short-term relief efforts for evacuees.

“An army of volunteers has come together to help with the influx of tens of thousands of evacuees,” said Saloomey. “In addition to shelter, they are providing food and clothing, not to mention medical assistance from local doctors and nurses.”

Some of the displaced who have moved to shelters have suffered from an outbreak of norovirus and other intestinal problems, she added, noting that about 30 people had to be moved into isolation in one shelter to prevent the disease from spreading.

“I was sick and vomiting for three or four days. Vomiting, diarrhoea, the whole nine yards,” said Dorothy Melton, who was staying at the shelter.

Refugees from the fire were also likely to suffer from mental health issues, according to Dr David Sprenger, a psychiatrist at the shelter.

He told Al Jazeera that he suspected there would be “a lot of post-traumatic stress disorder (PTSD)”.

“It may not be full-blown PTSD, but it may be just folks with nightmares, maybe a lot of sadness, irritability, people with trouble sleeping. That’s really common after this type of disaster,” he said.