My boy has been out for up to 4 hours, only on days where the sun is able to provide the essential heat and light.

I'm down in NZ, our winters are pretty chilly but having no ozone layer over us we get hot hot summers.
You also have to condition your beardie to being out. I kept him at home for 5 months to begin with, slowly introducing him to the outdoors. He used to freak out whenever a bird flew over! But once he was alright with being around other people and being held by anyone, I took him out to the city (as I live on a farm) Now out in the street I can hand over my dragon for "pats" knowing that he is safe and sound.
You wanna keep an eye on their belly, its a great indicator of how they feel.