Thermometers in the northern Montana city of Great Falls recorded an incredible temperature drop of nearly 40 degrees in just two hours.
At 3:53 p.m., the temperature was 52 degrees, about 11 degrees above the average high for the day.
During the next hour, the Arctic cold front pushed through and dropped the temperature to 19 degrees by 4:53 p.m. At 5:53 p.m., it was a frigid 13 degrees, completing the near 40-degree drop in two hours.
Residents of the city woke up to a low of 8 degrees Wednesday morning. While very cold, it was well short of the record low of -19 set in 1900.
Source: The Weather Channel