Here is an example of the effect of temperature on tube pressure. These are photos of one of my old Avon Redshanks (not a RIB I know, but it's still a fun boat, great for taking on a camping trip). The first photo is after the boat had been inflated in the afternoon. The second photo is the next morning, when it was about 30F cooler. This was in Maine USA, during the fall, when the temperature can swing quite a bit from night to day.
As the day warmed up the boat regained pressure without me adding any air. I always knew inflatables were sensitive to temperature, but I was quite surprised by how great the effect can be until I saw this. At least in this case the effect was to "deflate" the boat, so no worries about damage. You can imagine the potential pressure increase if the boat had been inflated on a cool evening and then the sun got to it the next day. I was always careful about not leaving an inflatable out of the water in the sun without deflating it a bit first. This made me even more cautious.