When can they live outside?

So I have two young boxies, one three toed and one gulf coast. My three toed is probably about a year old and my gulf coast is about 9 months old. They are roughly the same size and housed together in a rubbermaid tote. Their current enclosure is probably about 40 gallons. I'm not positive of my little ones' lengths/sizes.

I was thinking of building a small outdoor habitat for them, like the plywood juvenile boxes used by other keepers. After they outgrow that, I am planning to fence in part of the yard for them as a permanent habitat.

Are they old enough to live outside yet? Or would next summer (another year) be a better idea? I'm mostly just debating between buying them larger tote or making the move to outside.

I don't have Boxies, but I would house them outside for the warm days and bring them inside to sleep at night. @terryo might be able to help here.

I usually put mine outside for good when they are about three or four years old. Before that they go out in a smaller turtle garden just for the Summer. We have very harsh Winters here in NY and I'm always hesitant to leave the little guys outside to hibernate.

Thanks for the input. I think I will go ahead and build them something to stay outside in for the summer that is predator proof, and also look to upgrade their indoor housing.

I let mine out at 10 degrees Celsius but at 20 or over I always allow shade and water (in shade) the big danger is overheating, they can withstand cooler temperature (within reason) they just become lethargic when cool and cant digest food. The bigger danger is overheating.