British hill days have a habit of throwing everything at you: from horizontal rain on a Cairngorm plateau to fine drizzle in the Lakes. A waterproof jacket is your shelter, but the wrong one leaves you clammy and restricted. The trick is to balance protection with breathability, and to pay close attention to hood design and pocket placement. Here's what to look for when you're choosing a jacket for UK conditions.

Breathability: Keeping Your Own Sweat at Bay

Waterproofing is easy to measure: look for a hydrostatic head of at least 10,000mm, and preferably 20,000mm for exposed Scottish winter days. Breathability is more nuanced. It's usually given as a RET value, where lower is better. For active hillwalking, aim for a RET of 6 or below. A jacket with a RET of 3 or 4 will let far more moisture vapour escape, so you'll feel less soggy when you're working hard on a steep ascent.

But breathability is only half the story. Mechanical ventilation matters just as much. Pit zips – long zips under the arms – let you dump heat quickly without removing your pack. Look for two-way zips with storm flaps, as these are easier to adjust with gloves on. Chest pockets that double as vents are a bonus. No membrane copes perfectly with a heavy pack. Start cool, add a fleece when you stop, and open pit zips on the uphill.

Hood Design: Your First Line of Defence

A hood that doesn't fit properly is worse than no hood at all. It will flap in the wind, obscure your vision, and let rain run down your neck. Look for a wired peak you can shape to shield your face. Side and back adjusters let you cinch it close, whether over a beanie or a helmet.

A high collar that covers your chin keeps drips out. Some jackets have a fleece-lined chin guard, which is a small but welcome comfort on a cold day. Test in a shop: tighten the hood and turn your head. You should see your feet without the hood pulling away. If you wear glasses, make sure the peak doesn't direct rain straight onto the lenses.

Pocket Placement: Think About Your Pack and Harness

Pockets are where many jackets fall down. Handwarmer pockets at the waist are lovely for strolling, but useless when you're wearing a rucksack hipbelt or a climbing harness – they end up buried under straps, or worse, they create pressure points. Instead, prioritise chest pockets that sit high enough to be accessible with a pack on. A map-sized chest pocket is a genuine luxury on a wet day; you can pull out your map without exposing your core to the rain.

Consider internal pockets for your phone, compass, or snacks. They stay dry and don't interfere with your harness. If you use a camera or GPS, a small chest pocket with a secure zip is ideal. Avoid jackets with too many pockets; each one adds weight, bulk, and potential leak points. Two well-placed chest pockets and one internal pocket will cover most UK hillwalking needs. Make sure all zips are water-resistant and have decent pulls you can grab with gloves.

Fit, Fabric, and the Details That Matter

Fit is personal, but for layering you need enough room for a base layer and a mid-layer without the jacket feeling like a bin bag. Too tight, and you'll restrict movement and compress your insulation. Too loose, and the fabric will flap, letting wind chill you. Look for articulated sleeves – a slight bend at the elbow – and a drop hem that covers your backside when you bend over. Velcro cuffs should be adjustable and not bulky.

Fabric choice comes down to weight versus durability. A 2.5-layer jacket is light and packable, ideal for summer showers and fast day walks. A 3-layer jacket is more durable, breathes better, and is worth the extra weight for winter mountaineering and regular all-day epics. Whatever you choose, check that the main zip has a storm flap and that the seams are fully taped. A durable water repellent (DWR) finish will make rain bead up, but it wears off – more on that below.

Care and Maintenance: Keeping It Waterproof

Even the best jacket will stop performing if you neglect it. Dirt and body oils clog the fabric's pores, reducing breathability and allowing water to soak in. Wash your jacket regularly with a technical cleaner – never use fabric softener or biological detergent. Follow the manufacturer's instructions, but generally a warm wash and a low tumble dry will reactivate the DWR. If water still soaks in, apply a spray-on or wash-in reproofer.

Store your jacket loosely on a hanger, not crammed into a stuff sack for months. Check the zips and adjusters before each season. A little care will keep you dry for many years of British hill days. When you're choosing, remember that breathability, hood design, and pocket placement are the three pillars of a jacket that works with you, not against you. Get those right, and you'll be comfortable whatever the forecast throws at you.