I don't think humidity has anything to do with it. I live in the desert, it's not that humid I think it might be water retention. Your theory about cold makes sense. Biology was never my strong suit.
In this case, I think pregnancy was probably the culprit though (I can't find the dancing banana)
Humidity in the air and as in when its hot your body perspires. If you wear gloves your whole hand sweats more, if you wear a ring then just that little area sweats more.