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(CNN) -- Get ready to see the mercury plunge again.
Much of northern Plains, Midwest and Northeast will likely shiver through daytime high temperatures 10 to 30 degrees below normal through Wednesday, the National Weather Service said.
For example, Chicago could see a "high" temperature of minus-5 degrees Fahrenheit on Monday and minus-3 on Tuesday.
And a blizzard watch is in effect for North Dakota, parts of northeast South Dakota, western Minnesota and parts of central Iowa, where forecasts call for 2 to 6 inches of snow through Sunday and possible wind gusts of 60 mph.
New Orleans will see a high near 63 degrees Sunday, but by Tuesday residents there will have to prepare for highs only in the upper 30s.
In Atlanta, temperatures are expected to drop into the low 20s Monday night and the low teens Tuesday night.
Three cities have already set snowfall records for January: Detroit (31.5 inches), Flint, Michigan, (29.5 inches) and Toledo (36.4 inches). Fort Wayne, Indiana, and Indianapolis are experiencing their second snowiest January on record.
Jeffrey Goodman of Mentor, Ohio, snapped a photo of ice crystals for CNN iReport.
"It gets cold in northeast Ohio, but it's been awhile since we have had this many days of temperatures in the single digits," he said.
The bitterly cold winter is worsening a propane shortage that affects 12 million Americans who use the fuel to heat their homes.
Two dozen states have declared energy emergencies this winter, partly because propane supplies are running short while prices have risen sharply.
Supplies are short because of increased demand due to the cold weather and increased usage by corn farmers last fall who used it to dry a bumper crop of corn.
Some states, including Wisconsin, are allowing drivers of propane trucks to drive longer hours and increase the amount of propane carried in a single trip.
The shortage is especially acute for those who depend on propane to heat their homes during an extremely cold winter. Sandy DeHorn of Crete, Illinois, said the price per gallon recently rose to $5 from $2.69 per gallon.
"People are going to lose their houses," DeHorn told CNN. "You have a choice, you either pay for the propane or for a house to live in. What are you going to do?"
CNN's Susanna Capelouto contributed to this report.