Winter storm hits Central North Carolina, bringing ice and sleet

Nearly 4,000 flights have already been canceled within, into or out of the U.S on Monday, with flights leaving Boston and New York City hit the hardest, according to FlightAware.

There are 96 cancellations at Raleigh-Durham International Airport (RDU), as well as 37 delays.

Since Friday, more than 20,000 flights have been canceled nationwide due to the storm. Over11,000 flights were canceled on Sunday, marking the highest day for cancellations since the pandemic, according to Cirium data.

Flights are expected to resume Monday at Ronald Reagan Washington National Airport after the airport stopped all flights Sunday due to the storm.

ABC News contributed to this report.

At least 18 deaths have been attributed to the storm nationwide.

In Frisco, Texas, near Dallas, a 16-year-old girl died from a sledding accident, according to Frisco police. The victim and another girl were being pulled on a sled by a teenage boy driving a car when the sled struck a curb and then hit a tree, police said.

In the Austin area, a victim was found dead in the parking lot of an abandoned gas station from apparent hypothermia, officials said.

In Arkansas, a 17-year-old boy died after he was being pulled by an ATV in the snow and struck a tree, according to the Saline County Sheriff's Office.

In Lehigh County, Pennsylvania, three people died while removing snow, the county coroner said. The victims ranged in age from 60 to 84, the coroner said, adding, "I remind the public to use caution when shovel snow ... especially individuals with a history of heart disease or other medical concerns."

Five people died in New York City, according to the mayor.

In Massachusetts, a woman died after a snow plow backed into her in a parking lot, local officials said, according to Boston ABC affiliate WCVB.

Three deaths were reported in Tennessee, two in Louisiana and one in Kansas, according to officials.

People are starting to hit the road.

A crash on I-40 westbound closed the left shoulder at Exit 303 around 6:30 a.m.

A truck with a plow overturned on I-885 at I-40 eastbound.

A cold weather advisory will be in effect from Monday night through Tuesday morning.

Dangerously low wind chills are anticipated, with some areas reaching single digits above zero and as low as five below zero in the northern Piedmont and Coastal Plain.