One of the greatest temperature drop in 24 hours in the United States took place in Browning, Montana, on January 23, 1916. The temperature started at 44 °F (6.7 °C) and dropped to -56 °F (-48.9 °C), a drop of 100 degrees Fahrenheit within 24 hours because of an Arctic blast.
This was once recognized by the Guinness Book of World Records and the National Oceanic and Atmospheric Association (NOAA) as the greatest 24-hour drop in temperature ever recorded in the United States. But this extreme temperature drop was actually beaten in 1972, and it also occurred in Montana.
Between January 14th and 15th, 1972, a record change in temperature of 103 degrees Fahrenheit took place in Loma, Montana. The temperature went from -54°F (-47.8 °C) to 49°F (9.4 °C) within 24 hours. At the time, it was not known that the record had been broken. It was brought to the attention of NOAA’s National Climate Extremes Committee in 2002.
One of the reasons for Montana’s extreme temperature swings is because of the Chinook winds. These warm winds can travel down the east side of the Rocky Mountains at speeds up to 100 mph.