The snowboard jacket waterproof rating is one of the most important features of a snowboarding jacket. While the warmth of the jacket is what most people consider, the waterproof rating has a significant effect on the warmth. This rating is a measure of how much water the jacket can withstand before moisture begins to leak through to the skin. This is important when snowboarding as snow is obviously going to get onto the jacket, and as it melts it can seep through and get the skin wet. Moisture draws heat out of the body, which is of course why wet bodies get colder.
Snowboard jacket waterproof rating is measured in how many milliliters of water the jacket can withstand before a leak occurs. Generally this number is very large, so instead of being listed as milliliters it is listed in thousands of milliliters. For example, a jacket that can withstand 10,000mm of moisture would have a waterproof rating of 10K. The higher the rating, the more waterproof the jacket will be and the drier and warmer the one wearing it will stay. There are several factors that affect how high the waterproof rating should be for an individual's jacket.
For example, if you are buying a jacket to go snowboard for a trip that will only happen once or twice a year, a good middle of the road snowboard jacket waterproof rating will suffice. You want to enjoy your trip, but you will likely only stay out 4 to 6 hours at a time before taking a break and allowing the jacket to dry a little, and you do not want to spend an unnecessary amount of money on a jacket that will not be worn but a few times. However, if you go out daily, or spend 8 or more hours at a time on the mountain frequently, it would be well worth it to spring for a higher waterproof rating.
Whatever the snowboard jacket waterproof rating is, it will not stay that high forever. Material wear reduces the waterproof rating over time, making it necessary to replace a snowboarding jacket from time to time. While normal wear and tear in unpreventable, taking some extra precautions when it comes to caring for your jacket can make the waterproofing last longer. For example, do not wash in hot water or in the washing machine, and do not put it in the dryer. Hand washing in cold water and hang drying is the best way to clean it.