The climate change I'm talking about is going from indoors to outdoors, or when the seasons change from cool to hot. Just the other day I played outside for a few hours. It was relatively cool, in the evening but quite humid. Everything was fine. A few days later I took the bass out of the case the action was noticeably higher. I left it for a few days but it never rebounded and I had to readjust it. It seems that you have a bass in the air conditioning and take it outside for a while and then back to the same conditions the neck would return to its previous state? Obviously not! This has happened a couple of times before, usually around a gig, meaning I've taken the bass out of the house for a while. But its not always a problem. Most perplexing. Other instruments don't seem to care as much, or at all. I'm assuming its humidity doing this and not some other agent. I'm also assuming there's not much I can do about it or we'd all be doing it. Sigh.
This thread should be in the Setup section. Still, just adjust the truss as needed, unless you keep going in one direction. Some basses are more temperamental than others...different/insufficient seasoning of the woods and so on. As long as the neck seems to move back and forth, bowing towards both high and low action (depending on humidity levels), you're fine.
Every stick of wood reacts differently to changes of climate. It is normal. Some sticks react a lot, some sticks barely react at all. It is normal. There’s more to tuning an instrument than twisting tuner buttons, the tuner button part only works if the neck is set up for the conditions it is living in. It is normal, but that “normality” is dependent on the particular stick of wood you have.