MILFELD (Washington) • The weather has been brutal on opposite ends of the continental United States.

West Virginia is experiencing its worst flooding in more than a century, leaving 24 people dead and prompting President Barack Obama to declare a federal emergency.

On the other side of the country, a massive wildfire burning out of control in the foothills of central California has left at least 150 homes in ruins and damaged another 75.

CNN reported that the death toll of 24 in West Virginia is the nation's highest from flash floods since May 2010, when 27 people died in Tennessee, Kentucky and Mississippi. Up to 10 inches (25.4 cm) of rain fell on Thursday in the mountainous state, sending torrents of water from rivers and streams through homes causing widespread devastation.

There is a one in 1,000 chance of this type of rainfall happening in any given year, according to the National Weather Service.

High waters have washed away cars, trapped hundreds and cut power to large areas.

Some towns were completely surrounded by water and hundreds of houses and buildings have been lost, said Mr Tim Rock, spokesman for the state Division of Homeland Security and Emergency Management.

"There are going to be a lot of rebuilding, a lot of people without homes, a lot of businesses destroyed," he said.

Among the dead was an eight- year-old boy who was swept away while walking along a creek bank with his mother and sister, local news station WSAZ reported. His body was found after three hours of searching.

While the skies were forecast to be clear yesterday, cold fronts today and tomorrow are expected to move through the region, both with "high moisture count", the National Weather Service said in a Hazardous Weather Outlook bulletin.

Extreme weather has also taken a toll on California where the so-called Erskine fire, which broke out on Thursday 64km north-east of Bakersfield in Kern County, has already claimed at least two lives and forced thousands of people to evacuate their homes.

More than 1,100 firefighters have been deployed to battle the blaze.

California Governor Jerry Brown has declared a state of emergency for Kern County.

Firefighters were working in steep, rugged terrain against flames that were fuelled by hot, dry weather and brush, grass and chaparral left bone dry by California's devastating five-year drought.

AGENCE FRANCE-PRESSE, NEW YORK TIMES, REUTERS