Millions of people were stranded and thousands of flights were canceled as unprecedented snowfall hit the US East Coast.

The National Weather Service said up to 94 centimetres of snow fell in Rhode Island and Massachusetts. New York also reported heavy snowfall.

The state government warned that travel in New York was “impossible.”

More than 600,000 homes and businesses on the East Coast were without power, and states such as New Jersey and Massachusetts were also badly affected.

The snowfall was the highest on record, Candison Renssin, a meteorologist with the National Weather Service in Boston, told The New York Times.

“[It’s] completely broken the record; we’re shocked, like everyone else,” the newspaper reported.

Neighboring Rhode Island and Connecticut have also imposed travel restrictions on non-essential travel. Massachusetts Governor Maura Healy has also issued similar restrictions.

“All non-essential driving is prohibited in southeastern Massachusetts,” the governor said in a post on her social media page. “I have ordered the speed limit on major roads to be reduced to 25 kilometers per hour,” she said.

She added that the dense snow, which is blocking visibility, is making travel “extremely dangerous.”

“If you get into trouble, it’s difficult to get help… I urge everyone, no matter where you live, to stay off the roads,” she warned.

Nearly 300,000 people in Massachusetts are without power, according to poweroutage.us.

A travel ban imposed in New York City has left more than eight million people stranded. All roads, freeways and bridges have been closed.

In Connecticut and New Jersey, falling trees and branches caused by the snow are causing dangerous road conditions and there are concerns about power outages.