As long as it's warm enough and there's not too much of a breeze or wind i think either would be fine. Make sure there is shade it can get under so it does not have to stay directly in the sun.You don't want him to overheat or get too cold.
I wouldn't leave him outside unattended. There are other animals around that might see him as an easy meal. Also you have to think about insects-mosquitos, black flies, even bees or mites.
Oh, and in the future if you have a question you should start a new thread. You'll get faster/more response that way. If you don't know how, just come back here and ask.