I was in Norway in September with my 5DM3 + 24-70L mark 1. It was basically raining the entire time I was there, but I had an itinerary of hikes I had to do. I basically hiked with it in the rain constantly, and it held up just fine. It was normal rain fall, not heavy storm, and I had the camera in a holster case some of the time. The lens was weather sealed with a B+W slim UV filter.