Well there are a couple of things.. First.. Weather follows cycles, there is and 11 year cycle that follows SunSpots. and I'm not sure where we are but as I understand from Dr. T (Spaceweather dot com) we are at one end of that cycle. (Top or bottom I don't know) and if you like powers of 10, well there is another cycle that is around 100-110 years, and another (just and another Zero) and likely another still Longer.. Just keep adding zeros.
Plus there is the effect of industrialization which it seems adds heat.
BUT WAIT: What has SNOW to do with heat? (Actually that is a very good question, and as it turns out it has a very good asnwer)
As the oceans (Also lakes and streams) Heat up the water therein evaporates more easily.. and then it goes up to the clouds. and as they the song says "What Goes UP, Must Come Down" and it comes DOWN as SNOW.
So the fact that 2016 was the hottest year on record, and before that 2015 was, and before that, well you get the idea 2014 and 2013, Well.. That means we get more SNOW as well.. Because what goes up (Water) must come down (Flaky water).