Waterproof Ratings Explained

Waterproof Ratings in Ski & Snowboard Jackets - What does it all mean?

Ski & Snowboard Jackets have waterproof ratings to determine how well your new Jacket will perform in wet conditions. The higher the number, the more intensive rain can be before water will penetrate the fabric.

In short term; the higher the number, the less rain will get through.






Shower resistant     

Light drizzle


1,500 - 5,000

Water resistant

Light rain

Dry snow

5,000 - 10,000


Moderate rain     

Normal snow     

10,000 - 20,000     

Very waterproof

Heavy rain

Wet snow


Our Reccomendation:


We recommend a minimum waterproof rating of 5,000 mm for ski and snowboard jackets but only if you go out primarily in dry, clear conditions. A 5K rating will do the basics but just be aware that heavy snow fall, or plenty rolling around in the snow will get you feeling a little damp! 

If you're thinking “Why do I even need a waterproof jacket?” Well, you are likely to get covered in snow at some point during your holiday so have a think how much you value being dry.

So what do the numbers mean?

5,000 mm

5K will keep you dry in light rain or dry snow with no pressure.

10,000 mm

10,000 should suffice for most people who spend all day on the mountain, especially if you stay on the piste and dive into the nearest chalet when it pours down!

20,000 mm

If you spend a good percentage of your time in the backcountry or hiking or skinning to remote locations, breathability becomes equally as important as waterproofing – look for a jacket with both waterproofing and breathability in the 20,000 plus range.

What the Numbers Mean and why aren't all Jackets waterproof?

The truth is that all outerwear is designed for active winter sports and most Jackets will have various degrees of water resistance, but will eventually leak given enough water, time and pressure. Manufacturers define 'waterproof' according to different standards, and testing is not standardised. A rubber raincoat is completely waterproof, and may be the ideal garment for standing in a downpour, but if you tried to ski or snowboard in it, you'd b wet in time for your own perspiration. The trick is to balance protection from rain or snow on the outside with the ability to let perspiration escape from the inside.

Manufacturers typically describe the waterproof breathability of fabrics using two numbers. The first is in mm and is a measure of how waterproof a fabric is. In the case of a 10K or 10,000 mm fabric, you should technically be able to full a square tube over a piece of said fabric and fill it with water to a height of 10,000mm (32.8 feet) before water begins to leak through. The higher the number, the more waterproof the fabric.

The second number is a measure of breathability and is normally expressed in terms of how many grams (g) of water vapour can pass through a square meter of the fabric from the inside to the outside in a 24 hour period. In the case of a 20k (20,000) fabric, this would be 20,000 grams. The larger the number, the more breathable the fabric.