Outside....

[AndrewGeibel]

I would assume so as long as there aren't any pesticides/fertilizers etc that it could come into contact with.

[Alexandra V]

I don't see why he wouldn't be fine outside for that long if the temperatures are right. As was said, make sure there haven't been any pesticides there and make sure you watch to avoid him getting into a bad spot or another animal (dog, cat, whatever) getting at him.