CHICAGO/CLEVELAND, Ohio (REUTERS) - A blast of Arctic air gripped the vast middle of the United States (US) on Monday, bringing the coldest temperatures felt in two decades, causing at least four deaths, forcing businesses and schools to close and cancelling thousands of flights.
Shelters for the homeless were overflowing and the weather threatened to briefly curtail some oil production in the severe cold described by some meteorologists as the "polar vortex" and dubbed by media as the "polar pig".
Temperatures were 11-22 deg C below average in parts of Montana, North and South Dakota, Minnesota, Iowa, Wisconsin, Michigan and Nebraska, according to the National Weather Service.
More than half the flights at Chicago's O'Hare International Airport were closed as fuel supplies froze, leaving crews unable to fill aircraft tanks. The afternoon temperature in Chicago was minus minus 24 deg C, making it colder than in areas of Antarctica, parts of which hovered around 0 deg C during the southern hemisphere summer.
The Arctic air was moving toward the east coast where temperatures were expected to fall throughout Monday as low as minus 18 deg C in some areas on Tuesday. The coldest temperatures in years and gusty winds were expected as far south as Brownsville, Texas and central Florida, the National Weather Service said.
The north-east saw unseasonably mild weather and rain, but authorities warned travellers to expect icy roads and sidewalks on Tuesday.
At least four weather-related deaths were reported. In northwest Missouri, a one-year-old boy died on Monday when the vehicle he was riding in crashed into a snow plow on an icy highway, according to the Missouri State Highway Patrol.
In Indianapolis, firefighters found the body of an elderly woman outside her home early on Monday.
"It appeared she had been there for a while," said Captain Michael Pruitt of the Wayne Township Fire Department.
A 58-year-old man died on Sunday in northeastern Oklahoma after he lost control of his car on icy roads, the Oklahoma Highway Patrol said. In Chicago, a 48-year-old man died of a heart attack while shoveling snow on Sunday night.
In oil fields from Texas to North Dakota and Canada, the severe cold threatened to disrupt traffic, strand wells and interrupt drilling and fracking operations.
It also disrupted grain and livestock shipments throughout the farm belt, curbed meat production at several packing plants and threatened to damage the dormant wheat crop.
LIFE-THREATENING WIND CHILLS
In Cleveland, Ohio, where the temperature was minus 19 deg C and was forecast to drop to minus minus 21 deg C overnight, homeless shelters were operating at full capacity. Shelter operators had begun to open overflow facilities to accommodate more than 2,000 people who had come seeking warmth.
"There are also going to be people that won't go into the shelters," said Mr Brian Davis, an organizer with Northeast Ohio Coalition for the Homeless. Frostbite can set in within minutes in such low temperatures, according to experts.
The National Weather Service issued warnings for life-threatening wind chills in western and central North Dakota, with temperatures as low as minus 51 deg C.
The US cold snap mirrored or outdid freezing weather in parts of the world as Almaty, Kazakhstan where it was minus 22 deg C, Mongolia, where temperatures reached minus 23 deg C and Irkutsk, in Siberia, where it was minus 33 deg C).
Some 4,392 flights were canceled and 3,577 delayed, according to FlightAware.com, which tracks airline activity.
Many airlines could not allow their ground crews to remain outdoors for more than 15 minutes at a time. There were hundreds of cancellations by airlines including United, Southwest , and American.
"The fuel and glycol supplies are frozen at (Chicago O'Hare) and other airports in the Midwest and Northeast," said Ms Andrea Huguely, a spokeswoman for American Airlines Group. "We are unable to pump fuel and or de-ice."
After five days of scrambling to catch up from storm delays, JetBlue said it would halt operations at three airports in the New York area and Boston Logan International Airport from 5pm EST (10am Singapore time) Monday until 10am EST (11pm Singapore time) on Tuesday to give crews time to rest.
The bitter cold combined with blowing snow was complicating rail traffic as well. Union Pacific, one of the largest railroads and a chief mover of grains, chemicals, coal and automotive parts, warned customers on Monday that the weather was causing delays up to 48 hours across Illinois, Iowa, Minnesota, Missouri and Wisconsin.
Following last week's storm that dumped up to 60cm of snow on parts of New England, some shoppers opted for the comforts of home rather than venturing out to shop.
Many people did not have the luxury of staying home.
In the western Chicago suburb of Geneva, Ms Beth Anderson, 38, was shoveling the remains of Sunday's snow from her driveway before sunrise on Monday while warming up her pickup truck for the short drive to her job at a mall.
"I just wish I could get the day off too but it would take more than a bit of weather to close down the mall where I work," she said.