Understanding ski jackets

The hydrostatic head shows the water pressure the fabric can withstand, measured in millimetres. It describes the material, not the whole jacket: seams and zips are separate weak points.

Only compare values when the manufacturer states them. If the number is missing, the jacket isn’t automatically worse—we simply don’t know.

For days on the slopes, 10,000 mm is generally enough. If you often ski in snowfall, go off-piste or sit in the snow, choose 20,000 mm and look for taped seams.

With two layers, a lining hangs loosely behind the outer fabric, making the jacket feel soft and often padded. With three layers, the inner material is bonded firmly to the membrane and outer fabric. You mainly find this in shells for deep snow.

If you get cold quickly on the lift, choose a padded jacket. Synthetic insulation still keeps you warm when it gets damp; down offers high warmth at low weight. A shell has no insulation of its own: wear whatever you need underneath for the day.

The amount of insulation tells you how much material is inside. It doesn’t provide a temperature rating.

• A snow skirt keeps snow off your back when you fall or ski in deep snow.
• Ventilation zips let heat out when you’re working hard.
• A ski-pass pocket on the sleeve or chest saves you searching at the gate.
• A RECCO reflector can make it easier for rescuers to find you. It doesn’t replace an avalanche transceiver.

• Try the jacket on with the layers you plan to wear underneath.
• Raise your arms. The hem shouldn’t ride up, and the sleeves should cover your wrists.
• If you can, put your helmet on too and check the hood.
• Buy children’s jackets based on height. Jackets that are too large let snow in at the sleeves and hem.