I've heard conflicting things about the effects of weather on this war.
I read that Putin hoped it would stay cold so tanks could easily drive through open fields instead of sticking to the roads but the warm-ish temperatures turned the fields into marshlands and armored vehicles get stuck more easily (there's plenty of evidence that this has happened to quite a few Russian vehicles).
On the other hand I've also seen footage of snowy landscapes (probably from a different part of Ukraine though). Does that help the Russians? Who knows.