I wore this out on a 54 F day with rain and was comfortable. Temps after the rain got up to 59 F. Although it is not waterproof, it kept the water off of my head. My head did not overheat, and the very thin materiel fit well under my helmet that usually doesn't have enough space for a cotton cycling cap to fit comfortably. The cap fit is a bit large, which is nice because most cycling caps do not cover enough of my head to look good and feel comfortable. Usually the straps of the helmet are on top of the folds of the hat creating pressure points. I would recommend this to anyone who rides in cool temps and rain. Save money on the Assos Rain Cap and buy this!