31°C, New York
Notification products, updates
There is a particular kind of British hill day that no forecast quite captures. The cloud sits at six hundred metres, the drizzle is too fine to call rain but persistent enough to soak through a cotton shirt in twenty minutes, and the wind on the summit is doing its best to remove your hat. On days like that, your waterproof jacket is not a piece of kit you occasionally reach for. It is the thing standing between you and a thoroughly miserable descent. Choosing the right one is worth more thought than most of us give it in the shop.
The good news is that you do not need the most expensive jacket on the rack. You need one whose numbers and features match the walking you actually do. Here is how to weigh that up.
Waterproofness is usually expressed as a hydrostatic head in millimetres — a measure of how much water a column pressing on the fabric can withstand before it leaks. The test is done on a fresh sample in a lab, so treat it as a guide rather than a promise, but the ballpark figures are genuinely useful.
Two things matter as much as the headline number. First, taped seams: an untaped jacket leaks at every stitch, whatever the fabric claims. Second, the quality of the build — a well-made 15,000mm jacket will outlast a flimsy 20,000mm one. Ignore ratings quoted vaguely in a shop; look for the figure on the label.
Most hill walkers who complain their jacket "leaks" have actually been soaked by their own sweat. A waterproof shell traps warm, moist air next to your skin, and if that moisture cannot escape, you finish the day clammy and cold. Breathability is measured in grams of water vapour per square metre per 24 hours (g/m²/24h), or sometimes as a RET value, where lower is better.
Rough guidance: below 10,000g is poor; 10,000 to 15,000g is acceptable; 20,000g and above is good. But be realistic. No membrane keeps up with a hard climb in a full waterproof, and anyone promising otherwise is selling something. The technology that actually keeps you dry is ventilation — which brings us to the most underrated feature on any jacket.
Pit zips — long zips under the arms — are the single most useful feature on a hill-walking shell. On a long ascent you open them and dump heat; when you stop on a windy col, you close them and keep it. Packs with them and you can walk in a waterproof far more of the time, rather than stopping to strip layers every twenty minutes.
Other ventilation worth seeking:
Beware of a jacket so sealed up that the only way to cool down is to take it off. On a wet, windy ridge that is the last thing you want.
You will carry a shell far more often than you wear it, so it has to pack small and light enough that you never leave it behind. A three-layer jacket with a decent membrane typically weighs 300 to 500g and stuffs into its own pocket or a stuff sack the size of a large grapefruit. A lightweight two-and-a-half-layer jacket might come in nearer 250g, and is a reasonable choice for summer walks, though it will feel less robust in a gale.
Wind is the other half of the equation, and it is the thing British hills do best. Look for:
A shell should be roomy enough for a base layer and a fleece underneath, but not so baggy that it flaps like a sail on an exposed ridge. Try it on with the layers you actually walk in. Check you can raise your arms above your head without the hem riding up and exposing your kidneys to the wind.
Finally, look after the thing. Dirt and body oils clog the fabric and kill its breathability, and the water-repellent finish on the outside wears off with use. Wash it occasionally with a dedicated technical cleaner rather than ordinary detergent, and reproof it when water stops beading on the surface. A well-cared-for jacket will keep you dry for years.
Get the ratings, ventilation and fit right, and you will stop dreading the drizzle. You might even start to enjoy it.
Misty Combe shares practical, down-to-earth guidance on british countryside walking and rural life for readers across the UK.
Stay Tuned With Updates
Leave A Comment