The temperature then increased to 54 degrees (12 Celsius), only to fall back down that morning to negative 4 degrees (-20 Celsius), the Rapid City Journal reported .
The weather cracked plate glass windows and instantly frosted car windows, forcing drivers to pull over.
Meteorologist Susan Sanders said a combination of especially cold air from the north and east ran into warm air from the west.
"Warmer air came in and pushed (cold air) away," said Sanders. "When the winds let up, the warmer air retreated and the cold air came back."
Sanders said the air masses sloshed back and forth several times that remarkable morning 75 years ago.
The extreme temperature swings received national attention, including from "Ripley's Believe it or Not."
"There were newspaper stories from all over the country," Sanders said.
She said there wasn't much light-hearted news during the time, with World War II ongoing.
"It was something unusual that caught people's attention," Sanders said.
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