My boys go more than 3 - 4 times a day. So do I.
He should be able to last much longer than a hour, though. Usually they need to pee when they wake up (including from naps), after they eat, and after anything exciting like big playtime, or the doorbell ringing (if he goes nuts like my boys).
Great advice to keep him outside longer. Going for daily walks might help too. I know it is hard in the heat. We have go early morning and very late evening.