Due to the freezing conditions brought on by what feels to be the coldest Christmas in the State in 33 years, AAA issues a warning to tourists and residents of Florida that flights may be canceled.

Northern and central Florida experienced overnight lows in the 20s, and the Big Bend and Panhandle region are under a hard freeze warning that lasts until Monday at 9 AM.

Even though wind chills in many places may have made it feel that way, the temperatures did not actually break the record for the coldest Christmas. It's probably among the top five, trailing only the Christmas cold wave of 1983 and the Christmas of 1989, which continue to hold the record for the majority of the nation.

As of Sunday morning, authorities across the country had identified at least 18 fatalities as storm-related. Forecasters anticipate that the massive area of cold air covering the nation will continue to bring subfreezing temperatures into the following week.

According to the Weather Prediction Center, for the majority of locations in the South outside of south Florida, wind chills will still reach their lowest points Monday and Tuesday morning in the 20s and low 30s.

Canceled Flights

AAA advises the 112 million holiday travelers who plan to travel more than 50 miles to check their flights. There are still thousands of canceled and delayed flights.

The online flight tracker FlightAware reported nearly 13,000 delays and more than 5,600 cancellations for flights within, into, or out of the US on Sunday as of 5:00 PM ET.

With Denver having the most flight delays and cancellations, FlightAware's "Misery Map" showed over 900 delays in addition to over 200 cancellations between 2 PM and 6 PM ET on Sunday.

Where blizzards occur in the central and eastern United States, the National Weather Service issued a warning about whiteout conditions on the roads.

The National Weather Service said that traveling under these circumstances will be very risky, and occasionally impossible. There is a chance of getting lost and becoming more exposed to extremely cold weather.

Tallahassee Hard Freeze Watch

With subfreezing temperatures down to as 17 degrees as possible, the National Weather Service Tallahassee issued a hard freeze watch for parts of the Big Bend and Panhandle, which is in effect until 9 AM on December 26.

Jacksonville Hard Freeze Watch

Northeast and north central Florida are under a hard freeze watch from the National Weather Service Jacksonville until 10 AM on Monday. Temps as low as 25 degrees below freezing is possible.

Daytona Beach Freeze Watch

A freeze warning has been issued by the National Weather Service Melbourne for parts of Volusia County from later this evening through Monday morning. Temperatures as low as 32 are capable of freezing.

Read also: Significant Freezing Event in Northwest US Puts Ice on Runway, Sea-Tac Airport Flights Canceled 

West Palm Beach Hazardous Weather Outlook

A hazardous weather outlook for the Atlantic, South Florida, Biscayne Bay, Gulf of Mexico, and Lake Okeechobee was released by the National Weather Service Miami. In Glades and Hendry counties, wind chills in the lower 30s will persist into the early afternoon.

The remaining South Florida beaches have a moderate risk of rip currents, but there is a high risk along the Palm Beaches.

Naples Hazardous Weather Outlook

A dangerous weather outlook was released by the National Weather Service Miami. Later this afternoon and into this evening, the likelihood of thunderstorms will rise. There may be some strong to severe thunderstorms, especially to the north of Alligator Alley. The heaviest thunderstorms tonight over Southwest Florida could produce strong winds, torrential rain, and a lone tornado, Tallahassee Democrat reports.

Related article: Met Office Issues Two-Day Snow and Ice Weather Warning as UK Experiences Subzero Freeze