San Francisco, Dec 28 (IANS): This December has been a record-breaking month of snowfall in the Sierra Nevada mountain range in western US, scientists from the University of California, Berkeley's Central Sierra Snow Laboratory (CSSL) said.

At the CSSL near Donner Pass in northern Sierra Nevada with an elevation of 2,100 meters, 492 cm of snow has piled up in the final month of 2021, Xinhua news agency quoted the scientists as saying.

"NEW DECEMBER RECORD: 492 cm. With a 24 hour official #snow total of 98.75 cm at the lab, we have smashed the previous record of 455 cm of snow in December set in 1970! Snow rates are still heavy and we could break 508 cms today!" CSSL tweeted on Monday.

"That snow was deep and hard to get through to do the measurement. It took us 40 minutes to get from the front door of the lab to where the measurement is completed 50 yards away!" it tweeted.

The snow has been non-stop for days. Road conditions are treacherous with I-80 and Highway 50 both presently closed.

The Sierra Nevada snowpack is a major source of water for California.

According to the California Cooperative Snow Surveys, the state's average water equivalent is at 13.8 inches as of Monday, putting the state at 49 per cent of its average (through April).