Weather's a complex thing, for sure! As rekstout says, it all depends on topography, temperature bands and weather fronts (I'm just back from Austria where the temperature at ground level was -10C and it actually was snowing!).
If you have a look at www.snow-forecast.com, you will see that the biggest dumps of snow occur when ground temperatures rise significantly - that is why we tend to get snow for only 1-2 days at a time (we need a cold snap then a warm front - this is why a White Xmas is so rare!).
......and Antarctica is actually classed as a desert region in many places - the snow just blows around, and doesn't often fall!