BobbyG

I think they'd be too hot....at least for me. I bike year round down to 5F. At that temp I wear a light balaclava over my face and ears, plus a headband over my ears, and sometimes over that the hood to the hi-viz yellow windbreaker, which is enough, even with my highly-vented helmet.

You don't mention how cold a temperature you plan to ride in. I know that in Minnesota and Canada there are many who bike ride down below 0F and into the negative teens.

One of the best things I learned from bikeforums early on was to not overdress in the winter. Dress for 12 to 15 minutes into the ride when you are all warmed up. Less sweat equals warmer, more comfortable riding.

I've been commuting year-round for 30 years in Colorado Springs where it's usually in the mid-teens and 20s above 0F in the morning in the heart of winter.

Of course, everybody's different, and if a ski-helmet works for you, then use it.