The Answer
Guinness World Records cites the greatest temperature range in one day as 56°C in Browning Montana in January 1916.
A recent drop in temperature in Denver from 83°F down to 19°F (a drop of 64°F/36°C) in just 18hrs, got us wondering about the fastest temperature changes in the world.
Guinness World Records has only a single record for changing temperatures – greatest temperature range in one day. This was a 100°F/56°C drop in Browning, Montana in January 1916.
There are claims that this record was broken in 1972, with a 103°F rise in temperature, but that doesn’t seem to be acknowledged by Guinness.
Are there faster changes?
The fastest change in one day is only one way to measure the rate of temperature change (and not a particularly good one).
The Weather Channel reports on an extremely sudden temperature change in Spearfish South Dakota in January of 1943.
In Spearfish, the temperature rose from -4 at 7:32 a.m. to 45 degrees–a rise of 49 degrees—in just two minutes. A couple of hours later, it plunged from 54 back to -4 degrees–a change of 58 degrees in 27 minutes. In downtown Rapid City, the temperature had warmed to +5 degrees by 9:20 a.m., then it quickly warmed to 54 degrees by 9:40 am—a difference of 49 degrees in 20 minutes.
The Black Hills Remarkable Temperature Change of January 22, 1943
Disclaimer
This author recognizes that it’s quite unlikely that the most extreme and sudden weather shifts occurred within the United States. It is very likely that there is other (much harder to source) information that would reveal similar or more dramatic temperature shifts elsewhere in the world. We have simply (and lazily) drafted this post based on the most readily available information.