I had a similar thought for an OC the other day. I like scifi so a lot of my writing is set in space, and I thought it would be funny to have a character from a world that doesn't have rain getting freaked out when she sees rain on another planet for the first time.
"How can you all be so calm? There is water falling from the sky! That isn't natural!"
There's a scene in The Wheel of Time books where characters that lived all their lives in a desert region and were raised in a culture that treasures water more than anything venture out of that desert and see rains, rivers and lakes for the first time. The first reaction is basically "wait, all this water... is just free to take?"
Oh, Robert Jordan definitely was inspired by Dune when he was designing that desert culture. Very much warmongering and ruthless and full or rituals and stuff. Oh, and the main character, of course, turns out to be their chosen one
just for a point of comparison, Titan's atmopshere does have 'rain'... it's methane, mind, but it does have 'rain'.
Most likely, without some for of extensive environmental suits (or possibly entire environmental climate chambers built onto semi-mobile vehicles,)(I'm imagining the space chamber used by third stage guild navigators in Dune.) such won't be able to survive anyway. So they'd probably look at the rain and go "oh, that's interesting to look at." while sipping whatever passes for coffee.