I wear shorts if it's in the 60's and above, otherwise it's knickers or tights.

I almost always have a jacket with me (might be rolled up and stuffed in a jersey pocket); even if it's hot out, I will probably need it for descents. Plus I tend to run very cold.

I will ride in weather down to 20F but it's a challenge. Even with layers on, including 2 layers of gloves and socks, my feet and hands freeze.