Denver, as always, has proved to be a fickle weather beast this year. During the time between October 9 and October 11, Denver saw summertime heat, bone-chilling record cold, and several inches of snow. And there might be more on the horizon. 

So…what just happened?
On Wednesday, October 9, Denver saw a high temperature of 83 degrees. Then a cold front moved through, which dropped temperatures to 41 degrees in four hours and was accompanied by 55-mph winds that blew in from the north. Not only did the wind kick up dust from the Eastern Plains, they actually caused what is known as a Haboob—strong winds that carry dust—through the Mile High City. 

As the temperatures dropped, it was clear a big change in weather was coming. But we didn’t quite expect to see two record-cold temperatures, and a fourth-place tie for the largest two-day temperature drop ever recorded in Denver.

Of course, it’s not out of the norm for Colorado to experience drastic weather changes. Living in the High Plains means that we have a dry climate—bordering on desert—but officially, Denver has a semi-arid climate, and that allows for large changes in our weather. Plus, having no large body of water nearby works against us, as that could act as a hurdle or barrier to extreme weather shifts. When the arctic plunge of air moved in from the north last week, there was nothing to hinder it from coming into town with full force. And that’s exactly what it did. 

We broke some records, right?
Yes we did—some very impressive records! On October 10, the day after the cold front swung through and the snow fell, Denver dropped to 13 degrees. Denver was shivering from the cold airmass overhead and the snow-covered ground. Just before midnight on Thursday, we broke the old record on that same date of 17 degrees. 

But then temps kept falling. By Friday, October 11, temperatures at Denver International Airport (where official weather records for Denver are kept) fell to a bitterly cold nine degrees, which is kind of crazy for October, and yes, definitely a record (the previous was 22 degrees). That’s a rather large difference when talking about record-breaking temperatures. 

This swing in temperature—from 83 degrees to nine degrees—was so wild it made the number four spot for the largest two-day temperature change in the state’s recorded history, which goes back to 1872, and also ended up being October’s largest one-day (55-degree change) and two-day (70-degree change) temperature drop. 

Let’s talk snow!
Denver’s average first date of snow is typically on October 18, so this year’s first flurries came just eight day early. Most areas in and around Denver picked up from 1 inch to 5.5 inches—pretty impressive for the early season.  The snow also aided in the opening of two ski resorts, with Arapahoe Basin firing up their lifts on Friday, October 11, and Keystone opening on Saturday, October 12. 

Now what?
Expect some more ups and downs as we head into winter (hopefully not as extreme). We’re already watching for the next storm, which should hit around October 20. Longer range models are hinting at another significant shot of cold and snow around that time, but of course, anything can happen here in Colorado. Until then, get outside and enjoy the fall weather.

Andy Stein
Andy Stein
Andy Stein is a freelance meteorologist with experience working on both local and national television.