Los Angeles is experiencing what's already been declared by some as the worst fires in its history, with a spate of wildfires blazing through parts of the city.
The fires, which spread through densely populated areas, have so far killed five people, destroyed at least 1,000 buildings and forced tens of thousands of people to evacuate.
Authorities have said "hurricane-force" winds were fuelling the fires. The largest blaze is burning in the coastal neighbourhood of Pacific Palisades.
Despite California's long history with destructive fires, the fact that these fires are burning in unusually dry winter months has highlighted how climate change is reshaping fire seasons around the world.
Where are the fires and how did they start?
Fires are burning in the exclusive Pacific Palisades area along the coast near Malibu and Santa Monica Beach. These blazes have burned more than 6,000 hectares and destroyed at least 1,000 structures so far.
A separate fire in Eaton has burned through at least 4,000 hectares in the Los Angeles National Forest and Altadena area, near Pasadena in the city's north-east.
Another fire is burning at Hurst in the Sylmar region, on the city's northern outskirts in the San Fernando Valley. It's growing quickly and has prompted the evacuation of thousands of residents.
The new Sunset fire in the Hollywood Hills is also uncontained, sparking an evacuation order for tens of thousands of people. The area includes the iconic tinsel-town sign, the Hollywood Walk of Fame and the Hollywood Bowl.
The nearby Lidia fire has also prompted evacuation orders, but that blaze is being brought under control.
[LA fires map]Authorities say the exact cause of the fires is still being investigated.
What weather conditions are stoking fires?
Each year California experiences the Santa Ana winds, usually in the cooler months between September and May. Sometimes called the 'devil winds', the Santa Ana winds have fuelled some of California's worst fires.
These hot, dry blasts originate over the deserts of Utah and Nevada and blow across to southern California. Wind gusts peaked around 160kph in parts of the state during the fires, according to the National Weather Service.
"What ends up happening is that these winds are the offshore winds, strong winds that move and blow from the north-easterly direction out towards the ocean, and they get funnelled through the canyons of the mountains that surround the LA area," US meteorologist Jonathan Porter told the ABC.
Santa Ana winds also cause the humidity to drop extremely low, drying out vegetation and adding to the dangerous fire conditions. Usually in California, onshore winds carry moist air from the Pacific into the region, the Associated Press explains.
Greg Mullins is a former commissioner at Fire and Rescue New South Wales with more than 50 years' experience as a firefighter, and now works at the Climate Council. He recalls experiencing fires fuelled by the Santa Ana winds.
"They just drive fires, you don't even need the temperatures, if it's dry enough you'll get fires like this," he said.
"That's what surprised me in 1995 when I first went over there. The fires were crowning, going through the treetops and coming downhill at us.
"It was something I had never experienced before in Australia. We have wind-driven fires but they go fast uphill and slower downhill and that's when we catch them."
Isn't it winter in California?
These devastating fires are burning in what's usually California's wetter months, but the rains have not come this winter.
Downtown Los Angeles has recorded just 0.3 inches of rain since May. One-third of the state, mostly in the southern regions around Los Angeles, are in drought.
"There has been very little rain and typically … this is when southern California [would get] its needed rain for the entire year, during the winter months — it just has not happened," meteorologist Jonathan Porter explained.
"The jetstream has been located abnormally further to the north across the western part of the US, and that is directing all of these storms with rain and snow to the Pacific north-west … as opposed to southern California.
"You have to go all the way back to last April in order to get more than a quarter inch of rainfall in Los Angeles, so it has been so dry in recent months."
Before that, California was in drought for most of the decade until the winter of 2022-23. The state then had two years of consistent rainfall, which has allowed vegetation to flourish before drying out again.
"[That] caused vegetation to green up, which they had not done in years. And when it has been dry in the last several months, [vegetation] dried out and created a tinderbox," Porter said.
"Couple that with the gusty winds and it was the perfect storm for these devastating wildfires."
Drought and bushfires are the two biggest climate-fuelled threats that California is facing as global temperatures increase.
Is climate change driving wildfire conditions?
While California has always experienced what it calls wildfires, climate change is exacerbating the conditions they need to thrive.
"Climate change, primarily caused by the burning of fossil fuels, is increasing the frequency and severity of wildfires not only in California but also all over the world," the California Air Resources Board states.
According to the Intergovernmental Panel on Climate Change, California is becoming drier and hotter, and so drought and "fire conditions" are increasing.
Researchers have found that parts of Texas, California, Oregon, and Washington now experience fire weather more than twice as often compared to 1973. Drier winters, early onset spring and less snowpack melt are also attributed to rising temperatures and can exacerbate fire conditions.
"Climate change has changed fire seasons worldwide. Places like Australia and California that have always burned — are burning more. The fire seasons are longer," Mullins said.
With fire seasons starting earlier and finishing later in both hemispheres, Mullins says it makes it harder to share resources and crews between Australia and other regions.
"This is one of the critical risks of climate change," he said.
"The critical assets like large firefighting assets, we share [them]. So at the moment we have aircraft on lease in Australia from Canada and America that they could be using over there but they cant because we have them.
"This is a reality of climate change. How do you help each other when you're both burning?"
It's too early to say exactly how much worse these fires are because of climate change, but scientists will be looking to study that in the wake of this extreme weather event.
