I checked the tags that came with this and there is no rating. Here is what the tag says:
Fully taped seams - Thermal seam tape fully seals small holes created when sewing two pieces of fabric together
Waterproof/breathable - Fabric treated with waterproof coating. The fabric "breathes" by letting moisture vapor escape through outer layers while keeping out rain.
Built in vents - Strategically located vents allow airflow. Promotes cooling during active outdoor sports.
Self packable pocket - Jacket packs and stows into its own pocket. Great for travel and storage.
I haven't actually worn it in the rain yet. It is made from nylon that is treated with DuPont Teflon fabric protector. This tag says: Repels water and oil based spills. Saves time, dries quicker, saves energy.
This is a very nice, well-contructed jacket. I hope this helps you!