Yes, the weight of your ski balaclava matters because it affects how warm you'll be, how comfortably it fits under your helmet, and how easily you can stash it in a pocket. Balaclavas generally range from 30 to 200 grams. Lightweight options (30–60g) are great for spring skiing or as a thin liner, while midweight models (60–120g) hit the sweet spot for most standard winter resort days. Heavyweight balaclavas (120–200g) are built for extreme cold and usually feature thick fleece or windproof membranes.
A common mistake is assuming a lighter balaclava won't keep you warm. Modern fabric technology means a lightweight merino wool or synthetic blend can be surprisingly warm without the bulk. However, don't make the mistake of choosing the lightest option for bitter cold conditions, as you'll likely need that heavier insulation.
To choose the right weight, think about when and where you ski most. If you run hot or mostly ski on milder days, go lighter. If you constantly battle freezing temps and wind chill, a heavier balaclava will give you the protection you need.