The weather at lower elevations in Colorado changes from 1 day to the next. It's not uncommon to have snow in December, but it rarely lasts more than a day. Some of the fast moving winter storms can cause some serious issues along the I-25 corridor North of Colorado Springs, but its rarely bad in town.
When my family moved there schools and the City closed in September from a snow. Power lines were down and the snow plows were still in storage. After the desert and Yuma AZ I thought I was in heaven.. snow shoeing in the City in Sept.
This year we have not had much of any snow, even north of the Springs. However, snow can come at any time from Sept - May. That being said, snow in the "cold months" Dec - Feb is rarely very large and usually melts the next day.
We've been here for about 21 years and the weather seems to have really changed, with less snow and cold weather each year for several years. Seems like we haven't had near as many significant snowfalls either. Sure has been cold off and on!