Took this jacket out for a test run today. When I left the house it was sprinkling, but the clouds told me the rain would soon come pouring down. Initially they didn't. Sun came up, and I was worried I was going to be hot and obstructed by this jacket. Fortunately, the breathability is top tear, and the jacket is very light. Felt like a long sleeve light weight tech tee. Eventually the rain came down, along with the wind. Zipped the jacket up and put the hood on. Rain did not penetrate the jacket. Heard the heavy wind bussling by and felt its resistance, but didnt feel its cold. Top tier jacket. Got home and my hair was dry, my shirt only soaked in sweat (no rain) and feeling good about being able to run.