What is "too cold"
After three days of rain/fog/not enough time, i needed to get some sun on my bare ass. One of may favorite spots was empty, and the car's thermometer said "65" . So i gave it a try.
What a beautiful day. Just warm enough in the sun. A slight breeze to keep me cool on the uphill parts of the trail.
And it will be 71 today, so i will be out again.
So, at what temperature do you say "not today"?
Hi from the UK where we have the same issue. I tend to look for double-digit temperature, but that's Centigrade, of course! So 10C or higher - that's 50F or more. Wind is a major factor. As long as there is little or no wind I can be happily naked down to freezing temperatures, as long as I'm also active, e.g. walking. As soon as I stop for a bite to eat (or to find a geocache) that's when I can feel the cold.
A lot depends on what you're used to. In Australia they close outdoor swimming facilities if the air temperature goes below 28C (82F) - to us in the UK that would be a heatwave and we would want to 'cool off' long before then! So it's possible to 'acclimatise' yourself...
One hike I did a couple years ago was in Revelstoke National Park, BC. It was about 15 C that day and I was hiking for 2 hours. At the top where I turned around there was still snow on the ground, but I found one spot that was in direct sun and sheltered from wind and just lay there for a while. Unfortunately it was en route home while on vacation and the 5-hour drive to get there doesnt allow for an easy day-trip. Ive always wanted to go back.