I'm sure not an expert, but visiting the USS Missouri many years ago at Bremerton, WA, a sign stated that the interior of the ship was sealed and maintained at 33% humidity. Most of the time in So Central Montana, I'd have to keep a humidifier going to get the humidity that high.
I've tried to keep my guns, components, ammunition, and loading tools in a dry basement for the past 32+ years, and have to say that there's less light surface rust with the lower humidity here than in Seattle where it tends to be wet.
I'd have to say that drier is better than wetter, and cooler is better than hotter. Good luck if you live in a hot, humid climate which it looks like you do. A dehumidifier or a good air conditioning unit might be in order.
