I just wear an ear band. I put it on my neck, then the helmet and pull it up over the straps. That way I can pull it down later in the ride when I warm up without stopping to pull off the helmet.

Around here I can usually find one in the street over the course of a winter or get one out of any elementary school lost & found. So Cal you may actually have to buy one.

https://www.rei.com/product/103631/r...fleece-earband