I can only speak for my area, we have had some warmer then average times, but we have also had stretches of below average as well. If you watch the local weather, every time the temps are slightly above average, it is pushed about climate change, but crickets when the temp is below average.
Last winter we had maybe a little above average temps, but the winter before we had much below average temps. I personally have been seeing warmer temps in the fall, cooler in the spring. So a later winter, but later spring as well. Has the averages been warmer? IDK, my zone is still 3b, and it has been for many years. We probably have more -30 days then we get 90 degree days. And we probably get as many or more -20 days then 80 degree days.
If you look at a bigger piece of the pie and use decades, 70,80,90,2000,2010's for averages, I am not sure they get much warmer.