Record-breaking cold descends on eastern US
Bitterly cold air from Siberia has brought dangerously frigid and likely record-setting temperatures to the eastern half of the US.
Temperatures are 20-40F below normal for February from the Mid-Atlantic to the South.
Schools in Chicago have closed and trains in the north-east corridor have been affected by the cold.
Warnings of extreme cold are also in effect in the Canadian provinces of Ontario and Manitoba.
Frigid temperatures are expected to continue into Friday.
Record lows have already been broken in Kentucky, where it was -8F (-22C) on Thursday morning in Paducah and most of the state was below 0F (-17C).
Weather forecasters believe the cold air will help break more than 100 daily record lows, NBC News reports.
Forecasted Highs/Lows in the eastern US:
- Atlanta, Georgia: 29F/14F
- Chicago, Illinois: 6F/-1F
- Nashville, Tennessee: 18F/7F
- Philadelphia, Pennsylvania: 20F/1F
- Raleigh, North Carolina: 21F/6F
- Washington, DC: 18F/2F
In Atlanta, temperatures dipped to 15F (-9C) overnight and officials were trying to determine whether two people found dead had been killed by the cold.
The extreme cold is also threatening electricity grids in Tennessee. More than 30,000 homes lost power on Wednesday and officials are calling for residents to conserve energy as the state remains on an emergency footing.
Temperatures in Washington DC are set to reach 2F (-16C), the lowest in 20 years.
Even Orlando, Florida, was expected to see temperatures fall below freezing.
In Toronto, a three-year-old boy died after being lost for hours wearing only a T-shirt, diaper and boots.
Elijah Marsh was found a few hundred metres away from his home in -2F (-19C) temperatures but died in hospital.
The bitter cold comes after a series of severe snow storms across the US north-east. Residents of Massachusetts and further north saw more than 70 inches of snow within weeks, paired with sub-freezing temperatures.
More snow was forecast for parts of northern Maine and Canada as well as areas around the Great Lakes.