During warmer weather I can't get enough sun. Even at 50f I'm out there if no wind. At 40 I even put the larger couch in front of the windows ad move the back cushions so i can lay on them to be higher. of courswe all prefer nude sunbathing. But I go as barely legal as possible on a couple local beaches.
While is preferable to enjoy the sun while nude at higher temperatures to what is mentioned above, I agree it is possible to enjoy sunning yourself while naked in lower ones, if you're lucky enough to have your own sun trap or know of natural places outside to do it in. I enjoyed a couple of hours nude at the beach here in England about a week ago, behind a convenient rock to keep out of the wind it was perfectly OK to be naked.
I know a few other local nudists who do the same if the weather is like this, less hardy soles think we're mad, preferring outdoor nudity only when its at least very warm. Maybe its because I live nude at home year round I don't find it uncomfortable to be naked outside when its cooler, either in a sheltered spot in the sun, or being active and doing something like hiking, but if its windy its not so much fun.
But, I love to be nude in the sun much more!