I've dinked around with it for a few turns, but haven't run into any weather yet. You see a three-day forecast at the bottom of the intel map. And I believe weather can be toggled off in the game set-up, which gives you a difficulty rating that -- I presume -- affects your final score.
But mostly, the patch is some QoL stuff I wouldn't want to do without. Named units, named villages, hex outlines, and sight ranges, for instance. Yay!