A husband and wife have told of how they managed to survive a raging California wildfire – by jumping in their neighbour's swimming pool.

John and Jan Pascoe spent six hours in the blackened water, regularly taking deep breaths before disappearing under the surface to protect themselves from the heat and burning embers filling the night air.

Facing a choice between being burnt alive or dying from hypothermia in the cold water, the pair stayed in the pool for six hours as they watched the trees and their neighbour's house burn down.

"This was our only option," John, 70, told the LA Times. "We ran down here and we found our way into this pool.

"We waited until we needed to get in, and then the fire got here, and that tree behind us went up. When that tree went up it was hot. That's when we got into the pool."

Wildfires across northern California have now killed 31 people – making this the deadliest week of wildfires in state history.

The Pascoes had gone to bed on a clear Sunday night (8 October) when the faint smell of smoke began filling the air.

But with no fire alerts appearing on their phones, and no sign of flames nearing their home in the hills above Santa Rosa, they believed they were safe.

At midnight they received a call from their concerned daughter, Zoe Giraudo, from San Francisco, whose father-in-law's home 40 miles away had burned away. She told her parents to get out of the house.

"She said you gotta get out of that house and I looked out my window and there was a wall of flame," Jan, 65, recalled.

The pair grabbed their cat and drove down their long driveway. They were forced to turn back as flames blocked their path.

"We were in survival mode," Jan said. "What are we going to do? What are we going to do?"

As flames surrounded them, they remembered their neighbour's pool a third of a mile away.

After hurrying in its direction, they waited until the last minute, stripped off and jumped in.

They said they heard loud bangs as they stood in the cold water, possibly from exploding propane tanks. They had to wait until the fire had finished with their neighbour's house before it was safe to get out of the pool.

"I just kept going under," Jan recalled, saying it was the only way to survive. "And I kept saying, 'How long does it take for a house to burn down?' We were freezing."

To keep warm they held on to each other; fearing the worst, they told of how much they loved one another and their family.

After around six hours, the fire appeared to have moved on and the couple jumped out of the water.

They warmed themselves on the concrete steps, put on their melted shoes and walked hand-in-hand towards their own house, which they found in a pile of rubble and ashes.

John, an artist who lost dozens of his paintings, said: "We lost everything and we have to start over. After being here for 35 years it's a little hard to get my head around. But we'll be fine. We have each other."

With the fires still raging in parts of northern California's wine country, authorities warned the death toll could increase.

"We're not even close to being out of this emergency," Mark Ghilarducci, the director of California's Office of Emergency Services, said on Thursday afternoon.

The same day had seen teams with cadaver dogs begin a grim search for more of the dead, resorting in some cases to serial numbers stamped on medical implants to identify remains that turned up in the charred ruins.