Waterproof ski jacket ratings are usually expressed in millimeters (mm), which is an experimentally derived method of testing the pressure required for water to pass through the fabric; common waterproof ratings on the market range from 5,000 mm to 20,000 mm. This is usually indicated by the manufacturer as 5k, 10k, 15k, 20k …… etc. The larger the number, the better the waterproofing of the fabric, but also the regular maintenance of the ski jacket, otherwise the waterproofing layer or fabric will wear off, resulting in a loss of performance.
Catalog
Waterproof ratings: what do the numbers mean
- Below 5,000mm
“Waterproof” starts at 3,000mm, anything up to 5,000mm will only withstand light rain, and jackets with this rating are only suitable for park riding or outdoor fitness, not for wearing in rainy or snowy weather.
- 5,000 – 10,000mm
Between 5,000 mm and 10,000 mm, the waterproofness of the jacket increases slightly. Many generic brands have water resistance ratings in this range. This rating is good for skiing in good weather, but if it rains, your experience will deteriorate
- 10,000 – 15,000mm
10,000mm or 10k is usually the entry standard for ski brands, and water resistance in this range is enhanced
- 15,000 – 20,000mm
15,000mm is about to become the entry standard for many professional brands,15,000 mm is reliable and rugged for all-mountain, all-weather use. 15,000 mm is more Waterproof than most need.
- 20,000 – 25,000mm
You will see better performance when the jacket reaches above 20,000 mm. Most professional brands fall into this ‘performance’ or technical range, and 20,000 mm of Waterproofness is more than enough to ski or ride in even the harshest weather!
- 25,000mm and above
if it’s above 25k, then it’s never going to let water in
What is Breathability
Breathability, simply put, is the amount of water vapour that can escape through the fabric. Water vapour comes from your body sweating and a jacket with a high Breathability rating will not stop you from sweating – but what it does do is allow the water vapour released by your skin to pass through the fabric and be released. This helps to keep you dry and prevents you from getting wet and cold all over. High Breathability is the key to staying dry on snowy mountains or outdoors for long periods of time.
Measuring Breathability and choosing the right rating
The Breathability of a fabric is related to its ability to let sweat (in the form of water vapor) escape. It is measured by the amount of water vapor emitted per square meter of fabric over a 24-hour period. It is indicated in millimetres on the label of the ski suit, like the Waterproofing rating, and is almost always displayed immediately after. For example, a jacket labeled 20,000/15,000 has a Waterproof rating of 20K (excellent) and a breathable rating of 15K (also extremely excellent). A ski suit with a Waterproof rating of 8,000/5,000 won’t keep you dry for long. Don’t forget that a highly Waterproof jacket doesn’t have to be very breathable. A combination of highly Waterproof and highly breathable is desirable for ultimate comfort on the slopes.

Gore-Tex Waterproof rating chart
Brand | Fabric | Waterproofness (mm/24 hours) |
Gore-Tex® | Gore-Tex® (Classic) | 28,000 |
Gore-Tex® | Performance Shell | 28,000 |
Gore-Tex® | PacLite® | 28,000 |
Gore-Tex® | Pro 2L | 28,000 |
Do ski jackets Really Need to be Waterproof
ski jackets can be waterproof or water-resistant. Waterproof ski jackets are recommended as they keep snow and water out of the jacket and keep one warmer. Ski rain jackets are less expensive.
Why Waterproofing Helps to Keep You Warm
It prevents water from penetrating through the surface fabric and soaking the inside, and it also protects against snow, which can make you extremely cold and uncomfortable if it melts inside your jacket. The main purpose of a ski jacket is therefore to keep you warm and dry, and Waterproofing and insulation are both important to keep you dry and warm
What are all the different kinds of waterproofing, and what do they do
There are many different types of Waterproofing materials on the market. They all work in slightly different ways and the different Waterproof materials include product names such as GORE-TEX, Nikwax, Hipora etc. All jackets from major international brands of ski jackets contain at least one of these Waterproofing materials, most are a combination of two.
DWR, LAMINATES AND MEMBRANES EXPLAINED
- DWR Coating.DWR (durable water repellent) is a hydrophobic polymer that effectively removes water droplets from clothing by immersion or spraying onto the outermost layer of the garment, DWR tends to disappear through wear and tear; however, it can be reapplied if necessary
- Laminates.Usually a polyurethane laminate which is stitched or heat fused to the inside of the outermost fabric, it is a very durable Waterproofing material and more cost effective; the only downside is that they are relatively slow to expel moisture, so you may feel wet and cold when you are skiing
- Membrane.The key to Waterproofing, with the strongest water resistance and Breathability to keep you exceptionally dry even in the harshest conditions.
How Waterproofing and Breathability work together
Waterproofing and Breathability may seem like opposites, But Waterproofing and Breathability work in tandem .Waterproofing keeps the snow from soaking your body and keeping you warm, while Breathability keeps you dry inside.
The sun may feel warm when you’re on the mountain or outdoors, but the air is actually very cold, so keeping warm is always a priority.
Why doesn’t ‘Waterproof’ mean completely Waterproof
Waterproof does not mean completely Waterproof, as modern Waterproof fabrics use a semi-permeable membrane that allows water vapour to escape. This is called Breathability and means you don’t get wet with sweat. This is important in the mountains or outdoors because if you get wet, your body will get cold. Waterproof fabrics are therefore not completely Waterproof, otherwise the inside of your clothing will become wet and cold, no matter what the weather is like.
Types of ski jacket
Winter jackets

Winter jackets may not have many of the features of ski jackets, such as being lightweight and Waterproof, and winter jackets are not as flexible and breathable as ski
The main function of a winter jacket is to keep you warm. These jackets are not specifically designed for skiing and are unlikely to be Waterproof or have a high level of water resistance
3-in-1 jackets

The 3-in-1 jacket combines a protective outer shell layer with an insulating layer underneath. These jackets are usually Waterproof
The 3-in-1 jacket also allows the insulation to be removed. This gives a jacket a great deal of flexibility.
Shell jackets

Shell jackets are available in softshell and hard- shell
Softshell jackets offer some wind protection but are slightly less water resistant, they are designed to be highly breathable and lightweight which means you have a lot of freedom of movement while skiing
Hardshell jackets are generally better at keeping out wind, snow and rain than softshell jackets. They are still light and flexible, while also adding more wind and water resistance
FAQ
What Waterproof rating should a ski jacket be?
Clothing between 5,000mm and 10,000mm (10k) is a good choice. Avid skiers and snowboarders, especially those in wetter climates, should look for Waterproof ratings in the 10,000mm to 20,000mm range or higher.
Is 10K Waterproof good for skiing?
10k Waterproofing: A decent rating and the minimum you would want to wear for several hours on the slopes each day. Ski clothing with this rating will keep you dry for a good 2-3 hours in the event of snow.
Is 5000mm Waterproof enough for skiing?
Normally at least 5,000 mm Waterproof for skiing and snowboarding in cold but sunny conditions
Is 3000mm Waterproof good for a coat?
If you are buying a Waterproof jacket for walking or commuting, then a Waterproof rating of 2,000-5,000 mm will be sufficient. If you plan on skiing or playing outdoors, we recommend a Waterproof jacket with a rating of 5,000-8,000 mm.
Is Gore Tex 100% Waterproof?
Every product in the original GORE‑TEX products range is Waterproof, windproof, and breathable and many come with additional benefits.
Extended Reading
The Best Waterproof Ski Jackets of 2023