It's a gorgeous beautiful mild day and all my birds are in the coop. Why? They can go in and out as they please, but they choose to stay inside. Should I push them out the door and close their little hatch?
Leave them safe passage to cover! Mine all run for cover when a hawk or other winged potential predator is around, even if we humans don't notice it. Mine also spend a good deal of the day in the barn that encloses their coop because they have little of no protection from the sun outside it. They seem to prefer to be outside in the evening when the barn is casting shadows and the sun is not quite so overpowering. If you want t encourage them to come out, try adding some other forms of cover in their pasture or run.