Hi, 'Blistering' is used to emphasize the cold. To make a temperature seem more extreme. I've heard 'blistering heat' more often, being from Florida. :) It's as to say, the cold/heat is so extreme that blisters or sores can form on the skin. I hope this helps.

I have not heard of blistering cold. Blistering heat, certainly. Bitingly cold is the more usual expression.

It means when the air is freezing cold and dry instead of air that is freezing cold and wet or humid if that makes sense.

It means it's really cold :)