NOTHING happens to Clemence in the rain. I have told this story too many times to count but here goes....
I was on an international flight of about 4 hours, sitting in a bulkhead seat with my Clemence Evelyne PM on the floor in front of me. The kitchen/galley on the plane ruptured at the base of the wall and flooded the first three rows of the cabin with water (gross coffee water) to the point that my row was 2 inches deep in a puddle.
My Evie was completely soaked through as if it had been in a wash cycle. I blotted it with a few paper towels which did not help but we still had 2 hours of flight time left and it did not dry. I went through customs with my bag literally dripping water on the floor (embarrassing), and then had a 90 minute drive. I laid the bag out flat in my hotel for a day and it finally dried.
My bag is FINE except for very minor stretching of the pocket where objects were stored, because I had nothing else to carry my things in while the bag was wet for SEVERAL hours and I needed to clear customs and then drive. Everything inside it was either damaged or ruined, including a Sombrero Ulysse and a scarf. The bag IS black so I can't say what would happen to a light-colored bag with dirty water, but all this "Clemence blisters in the rain" stuff is totally false and comes from one misinformed blog. My bag survived a full soak with no drying for at least five hours.
I also own 3 Clemence Evie TPMs and had a Clemence Birkin for years til I got my Barenia B. All FINE in rain.
Clemence is nearly indestructible and you may be confident in rain
Every time someone asks if Clemence can get wet, I think of you and this story!