This is a great example of weather and not climate. There are always one-off weather anomalies like snow one day in May or a 72 degree F day in December, but it's not good when these happen frequently.
Globally, the trends get warmer and warmer every year. Just because there was a warm December day 40 years ago doesn't really mean anything. What means something is these days keep happening more and more everywhere, and this has long term implications for everything. It won't be our extinction event but as other have said, we won't be living in the same world we are now.
Cinco