Yea they will still need a light depending. Is the cage always in the sun or are u moving him out there from inside? If your moving him out there, you should minimize the handling and keep him in his cage. The outdoor days should only be a treat for him..maybe once a week or so. He will get his required amount of UVB from the lights. If he is permanently outdoors..he can regulate it on his own and a light is not required...