Gear & Tech
A jacket can be sold as waterproof at 1,500 mm. What the ratings actually measure, why yours feels like it leaks, and the details worth more than the…
By Prakash Tamang · Sep 5, 2026
A jacket can be sold as waterproof in the UK at 1,500 mm of hydrostatic head, and most people would call that jacket wet after an hour of real rain. The number on the swing tag is a floor, not a promise, and it describes the fabric rather than the garment you…
Travel Himalaya Nepal · News
Hydrostatic head is a pressure test, and it is the number every rating comes from. A machine pushes water against the fabric at increasing pressure until three drops appear on the other side, and the pressure at that moment is the rating. That is a laboratory…
Travel Himalaya Nepal · News
It is almost certainly wetting out, and that is a surface problem, not a membrane failure. The outer fabric has a water-repellent finish that makes rain bead and roll off. That finish wears away with dirt, packing and time. Once it goes, the outer face soaks…
Travel Himalaya Nepal · News
Water gets in at the openings and heat gets trapped at the shoulders, and no millimetre figure describes either. Rain runs down your neck past a hood that does not cinch, up your sleeves when you use trekking poles, and through a zip with no storm flap behind…
Travel Himalaya Nepal · News
For most travel, a light 10,000 mm-class shell with taped seams, a wired hood and pit zips is enough, and it should cost well under the flagship price. You are buying the details, not the headline number. The premium is worth paying in one situation…
Travel Himalaya Nepal · News
Best overall
Outdoor Research Helium Rain Jacket
Light enough that you actually carry it, which is the only property that matters in a shell — the trade is a thin fabric that will not survive being dragged across rock.
↑ Swipe up
Light enough that you actually carry it, which is the only property that matters in a shell — the trade is a thin fabric that will not survive being dragged across rock.
Not for: Monsoon-season trekking where you will be in rain for hours daily. Take a heavier three-layer shell with pit zips.
Check price on Amazon Read the full reviewIf you buy through that link we earn a commission. It costs you nothing and it does not change what we recommend — the rental and advice-only entries in our gear guide earn us nothing at all.
Best in sustained rain
Arc'teryx Beta Jacket
Keeps working after six hours of rain when lighter shells have wetted through; you carry the extra weight every dry day too, and the price is genuinely hard to justify for one trek.
↑ Swipe up
Keeps working after six hours of rain when lighter shells have wetted through; you carry the extra weight every dry day too, and the price is genuinely hard to justify for one trek.
Not for: An October or November trek in the Khumbu, when it barely rains. The Helium is the better buy for that season.
Check price on Amazon Read the full reviewIf you buy through that link we earn a commission. It costs you nothing and it does not change what we recommend — the rental and advice-only entries in our gear guide earn us nothing at all.
Nepal is the honest test, because from roughly June to September the rain here is not showers. Nothing you can wear stays dry through days of it, which is why our guides talk about drying systems rather than waterproof ones — a lodge with a stove, spare dry…
Travel Himalaya Nepal · News
Plan your trek
NMA-certified guides · permits sorted · 5,000+ treks since 1998.
$920 pp
Free guide
Permits, costs, seasons and routes — the essentials we send every traveller, plus a free, no-obligation trip quote.
↑ Swipe up
Read the full report and grab the free Nepal Trek Insider Guide — or ask our Pokhara team for a tailored, no-obligation quote.
Read more & get the free guide Plan my trip — free quote Browse Annapurna Base Camp Trek — 9 Days