I live in the Phoenix area, and I keep all of my tortoises outside full-time. This time of year, he will be fine. You don't need to worry about him cooking or freezing.
My tortoises (leopards and stars) are active from about 7-9 am, and then again from 4-6 pm. Sometimes I absolutely can not find my leopards which have a huge area to roam. Even the 14" female seems to "vanish" at times. If I don't see one of them for a day or two, I make a point to walk around outside during one of the two "active" times, and I will almost always see all of them within a day or two. They just happily graze in the yard during those times. If you have grass, you should be able to catch your little guy enjoyng it during those times.
My tortoises (leopards and stars) are active from about 7-9 am, and then again from 4-6 pm. Sometimes I absolutely can not find my leopards which have a huge area to roam. Even the 14" female seems to "vanish" at times. If I don't see one of them for a day or two, I make a point to walk around outside during one of the two "active" times, and I will almost always see all of them within a day or two. They just happily graze in the yard during those times. If you have grass, you should be able to catch your little guy enjoyng it during those times.