Where in the USA would you prefer? It's a big place
l have several lists in my files somewhere of various storage facilities and I can look to see how many are climate controlled.
Climate controlled can have several meanings too. Some are heated only, some a/c only, and some both and it will depend on what part of the country they are located. The ones in Alaska (or in western Washington or western Oregon), for instance, will have only heated facilities as they really have no need for a big a/c controlled building as it rarely gets that hot in the summer to need it. Some places in the desert southwest have only facilities that have a/c with no heat as seldom will a prolonged hard freeze occur in the winter where there's a threat of RV pipes cracking as just being indoors during the short freezing temperatures at night is usually not enough to cause damage because just because of being indoors and sheltered from wind and exposure to elements ...yes, it will get below freezing at night but usually not long enough to cause damage to vehicles stored indoors.
Off the top of my head, I'll give a few now:
Friends of ours in the Tri-Cities area (Richland, Pasco, Kennewick) of Washington state have in the past used Broadmoor Storage and were pleased. I believe their facilities are both heated and cooled but you'd have to check to make sure. ...
go HERE for their website.
When we were in the Cleveland area some years back, an acquaintance recommended a storage facility to some relatives of ours. I believe their facility is only heated but you'd have to check. ...
go HERE for website.
We discussed this place in a recent thread and it's located in the Nashville area. It is brand new and getting ready to open in the near future. ...
go HERE for Safe Motor Storage website
These mentioned are "community" storage where all boats and RVs re in the same building. There are also place where you have your own stall but that's more rare and tend to be a lot more expensive.