We went from a high of 69 degrees Sunday to a low of 10 degrees Monday morning. That is a 59-degree temperature swing in two days.
While a huge change, that number doesn't even make it into the top 9 for "largest two-day temperature change in Denver" since records started being kept in 1872.
The winner of that category goes to Dec. 14, 2008 when we went from a high of 58 to a low of -18 degrees the following day! That's a 76 degree temperature swing.
The National Weather Service office in Boulder keeps track of these large temperature changes and places them into two categories: "Denver's Largest 1 Day Temperature Change" and "Denver's Largest 2 Day Temperature Change."
The largest one day temperature change tracks any given temperature swing from midnight to midnight during one calendar day. For example, Denver's largest one day temperature change came January 25, 1872. Between midnight Jan. 25, 1872 and midnight Jan. 26, 1872 temperatures went from 46 degrees to -20 degrees -- a swing of 66 degrees in one day.
The largest two-day temperature change tracks the data from midnight one day to midnight two days later. So, between midnight on Dec. 14, 2008 and midnight on Dec. 16, 2008, the temperature went from 58 degrees to -18 degrees, a swing of 76 degrees in two days.
You may be asking, "Why can't we just call it a 24-hour temperature change?" The answer goes back to technology.
In 1995, ASOS, or an Automated Surface Observing System, was installed at the brand new Denver International Airport. Among other things, this piece of technology records temperatures every minute, 24 hours a day, every day of the year.
This is something that was definitely not done back in 1872, when weather records started being kept in Denver. Until 1995, we did not keep track of when, during the day, a high temperature or a low temperature was reached. All we knew is what the high and low were for a specific calendar day.
That's why the categories stand at "Denver's Largest 1 Day Temperature Change" and "Denver's Largest 2 Day Temperature Change."
Record keeping and climate data will look very different in the next 100 years because of this advancement. But for now, and for the sake of accurate scientific recordings and comparisons, the above categories will remain unchanged.
To take a look at Denver's largest temperature changes of the years, click here.
