Heatwave stokes Los Angeles bushfire

A bushfire spreads on a hillside near a home in Burbank, California. Several hundred firefighters worked to contain the blaze. Photo / AP

A fast-spreading bushfire north of Los Angeles forced hundreds of people to evacuate their homes as firefighters struggled against triple-digit temperatures and erratic winds to contain the blaze.

Within a day, the fire - named the La Tuna Fire for its origin in La Tuna Canyon to the north of Burbank - had grown to cover more than 20km, according to the Los Angeles Fire Department. In all, about 300 homes in Burbank, 250 homes in Glendale and 180 homes in Los Angeles were under evacuation.

The fire was 10 per cent contained.

Los Angeles Mayor Eric Garcetti confirmed that the blaze was the largest in the city's history.

A fire burning near California's Yosemite National Park has entered a 2700-year-old grove of its famed giant sequoias, which are among the largest and longest- living organisms on Earth. The Nelder grove holds 106 ancient sequoias, including one of the world's largest, the 24-storey-high Bull Buck sequoia. It was unclear of any of the trees had been destroyed.

California has been experiencing a severe heat wave.

Carol Smith, a National Weather Service meteorologist, told the Los Angeles Times that a combination of conditions were working against firefighters: temperatures of up to 40 degrees C, 80 km/h gusts of wind and unstable air. "It just really stokes the fire. I mean, when it's hot and the gusty winds, it's been a bad mix of different things."

The Western United States baked through the unofficial end of summer, as temperatures in some parts threatened to peak at levels not seen in decades. Areas inland from the San Francisco Bay Area could reach 46C, a temperature last seen in 1950, forecasters said. San Francisco on Saturday set an all-time high of 41C.

The warmth extended up the West Coast and into mountain states. Fire weather warnings were in effect for parts of Wyoming, South Dakota and Montana. In the Pacific Northwest, high temperatures and a lack of rain this summer have dried out vegetation that fed on winter snow and springtime rain.

It's hot out there

On Saturday, San Francisco, US, reached its all-time highest temperature of 41C.

In July, Death Valley, US, endured the hottest month ever recorded on Earth.

In late July, Shanghai, China, registered its highest temperature, 40.9C.

In mid-July, Spain posted its highest temperature ever recorded when Córdoba airport hit 46.9C.

In late June, Ahvaz, Iran, soared to 53.7C - that country's all-time hottest temperature.

In May, Turbat, Pakistan, hit 53.5C, tying the all-time highest temperature in that country and the world record temperature for May.

- Washington Post, AP