Everybody is going to post something different. It comes down to what kind of energy you're putting out on any given ride, and how much heat you just put off as a person. I've done extended climbs (I know the OP has no chance to do these) below 30º in short sleeves, no gloves, with my helmet off, because I'm apparently an inefficient beast just pouring heat into the atmosphere-- even at freezing temps, while climbing my helmet becomes a sweat bucket. This morning's soaking wet splash fest was 45-50º and did I mention wet? and I was in shorts and short sleeves, fingerless gloves-- same thing I wear when it's 100º. Had to put my shoes in the dryer again, second time this week.