Seasons and Calendar Changes

I cant help but notice that going into the 1st official week of summer that I have yet to turn my air conditioner on. I do not have children and/or pets in my household and am in good health for my age range. This does increase my threshold for higher temps as they progress but I still find this as a notable trend. Does it seem like we can all remember our youthful days of the 70's and 80's where snow in October and November was common place. Now it seems like we get major snow falls in February/March at least in the mid-west states like Michigan, Ohio, Indiana etc. Likewise it seems like our Septembers and Octobers have more and more summer temps overlap. I can remember a very warm weekend in September last year that I should have turned on the AC for my guests and I but I held steadfast to a very stubborn rule "no AC in Sept are you kidding me". But now seeing me go almost into July without my AC lets me see how the timing of the seasons have shifted and how silly I was to make that decision.

People can debate long and hard whether this seasonal shift is caused or not caused by pollution/natural phenomenons etc... but the main question is, if the normal seasonal temps/activity still occur does it matter?