Not intending to contradict, but, it seems like I remember many Christmas seasons with very cold weather, sub zero stuff. I remember going to visit friends and having it absolutely freezing outside. Very cold! Then other times when it was warm.
Odd weather doesn't really strike me as different then what normally cycles over the years. In fact, I remember in the 60's when we would have continuous sub-zero weather for weeks on end. I don't recall many of those in recent years. Maybe my age helps because I was having to deal with grown up things during those time periods, but, they did exist and did in what seems to me to have been cyclical episodes. Even southern weather is changing in the opposite direction. I remember traveling down here in the 80's and if they had a snow storm, which was not often, they had no equipment at all to deal with it. The solution was wait until it thawed. (probably the next day). Now winter seems to invade much more often and cities and states have had to invest in snow removal equipment. Even the summers are cooler. It has been 4 years since the temperature has reached over 100 degrees in NC. When I first moved here in 2011 it was there for the entire month of July. So to me it is something that I notice as climate change, not exactly the same as global warming because that isn't the case everywhere, but, just a general change in local climates gradually happening all over the world. Overall, not necessarily constantly, the north is warming up and the south is cooling down. One doesn't even need a scientific study to actually notice it. It's cold right now up north, but, really doesn't have the sustained cold, massive snow, etc. as once was common. The south doesn't stay balmy year round either. Who knows, if I live long enough I might have to move back up north. I haven't started packing yet, but, I am storing sturdy boxes just in case.