Here is the bio on the guy who stated 100% humidity at night. He's been there and observed them in the wild:
https://chameleonacademy.com/member/petko-dvorak/ . I just go off of what they witness--probably way more accurate then my gut instinct, especially since they are actively seeking out chameleons and
then testing humidity to be as accurate as possible.
And here is Necas' care/wild info on Veiled Chameleons:
https://www.chameleons.info/en/chameleo-calyptratus/ which states for 100% humidity.
How do you know that they don't have the climate to get up to 100% humidity? What is this based on? I could come to the same faulty conclusion based on the humidity in my own region. Like you said, humidity (relative humidity and dewpoint) depends on many factors.
We shouldn't make estimates based on our own climate especially since Sweden is vastly different than Yemen--the climates are going to be completely different. The distance between Sweden and Yemen is huge! For people here in the united states, it would be like basing the climate of Guatemala on the climate from Northen Canada. Yemen and Guatemala are super close to the equator while Northern Canada and Sweden are very very very far from the equator. The climates aren't even comparable.