How to choose a rain jacket

Water column: how waterproof is it?

Makers state how waterproof a fabric is as a water column in millimetres. The higher it is, the more pressure the fabric takes before water gets through. A low rating is fine for a short shower, but on a bike the fabric is pressed against your body and your backpack. Choose a clearly higher water column then.

If the label only says 'water-repellent', the fabric is treated but not waterproof. Fine for drizzle, not for an hour of headwind on a dyke.

Seams and zips

Water often comes in through the seams, not the fabric. Taped or welded seams are sealed. Also look for a zip with a flap or waterproof coating, and a hood you can tighten so it doesn't blow over your eyes.

Breathable, so you don't get wet inside

A fully sealed jacket keeps the rain out, but also your sweat in. Breathable fabrics let moisture out. If you cycle any distance, you'll feel the difference at once. Vents under the arms help too.

On the bike

A cycling jacket is longer at the back, so your back stays covered when you lean forward. Reflective details make you more visible in the dark. Sleeves that cover your hands and a collar that shields your chin make a difference in winter.