As the saying goes, "it's not cold when it snows, but it's cold when it melts." Tell me why. (sophomore physics)

Solidification releases heat when it snows, and melting absorbs heat when it melts.

The condensation of water vapor before snow has released heat, and the temperature has risen at that time;

When snow melts, it needs to absorb air heat, so the temperature will drop, which is really cold compared with the temperature before (and when) it snows.

So there is this sentence: snow is not cold, snow is cold.