A winter storm led to unusually heavy snowfalls in the western United States.

According to authorities on Monday (local time), one meter of fresh snow fell within 24 hours in California's Sierra Nevada.

All in all, this month saw more snow than ever in December since records began.

For the state, which is suffering from the consequences of a drought that has lasted for years, the heavy snowfalls are not only a glimmer of hope, but also a glimmer of hope because they could replenish the groundwater reserves.

By Monday, the total amount of snow in the Sierra Nevada, at 4.92 meters, exceeded the previous December record of 4.55 meters from 1970. And another 20 to 30 centimeters of fresh snow was expected for the next 24 hours.

"We certainly weren't expecting a wet winter," said Andrea Schwartz, a scientist from the Central Sierra Nevada Snow Laboratory at Berkeley University.

The abundant snowfall was "a pleasant surprise".

It is too early to declare the drought over, "but it looks as if the west of the USA is getting help with it".

The immediate effects of the storm were less positive: tens of thousands of people were affected by power outages, numerous blocked roads caused traffic chaos.

According to utility company Pacific Gas and Electric, the storm toppled electricity pylons.

The company announced that the power supply for almost 50,000 households had been restored since Christmas Day.

It expects further failures.

At Seattle Airport in northwest Washington State, the snowfall led to hundreds of cancellations and delays, and planes had to be de-iced.

Mayor Jenny Durkan warned of a prolonged cold spell with heavy snowfalls.

As a precaution, you have declared a state of emergency in order to be able to activate all resources for the protection of the residents.

Winter storm warnings also applied to large parts of the neighboring state of Oregon.

The southern state of Texas, meanwhile, experienced unusual heat for the time of year.

On Christmas Day, 34 degrees Celsius was measured in the Rio Grande Village ranger station near the Mexican border.

Scientists agree that climate change is leading to a significant increase in extreme weather conditions worldwide.