It could be because of the weather and temperature. It could also be because you just caught him drinking almost all the time that's why you're thinking that its unusual?
My Hamsters Drinking a lot, is this Normal?
He either has diabetes or a bladder & kidney infection. Take him to the vet ASAP.
I think hes okay but you need to take him to the vet just in case
Well maybe its really hot maybe take it out side if its not hot out, or just put it in air condition. Then if it stops drinking that means it was dehydrated.