What is the most drastic change in temperature in the United States on record?

The call is close.

Over the course of 12 hours in Granville, North Dakota, on February 21, 1918, the temperature rose 83 degrees.

It went from –33 degrees Fahrenheit in the early morning to 50 degrees near the end of the afternoon.

But in Fairfield, Montana, over the course of 12 hours on December 24, 1924, the temperature dropped 84 degrees.

It was 63 degrees Fahrenheit at noon, falling to –21 degrees by midnight.