Overtrousers for the hills

What the hills demand

A hill day combines long exposure, wind-driven rain, hard physical effort and a long way to go if something goes wrong. Wet legs in a strong wind lose heat fast, and on high ground in the UK that is a genuine safety issue, not just a comfort one. Mountain rescue teams and outdoor instructors consistently list waterproof trousers alongside a jacket as essential hill kit, whatever the forecast in the valley says.

At the same time you are working hard, often uphill, so a heavy non-breathable pair will leave you damp inside. The ideal is a genuinely waterproof, reasonably breathable pair that is easy to get on over boots in a gale.

Features that matter

• Long side zips. 3/4 or full-length zips mean you can pull them on over boots while balancing on a wet hillside, and vent the lower leg on the climb. Full-length zips are worth their weight in winter, when you may be wearing crampons.
• A solid waterproof rating and taped seams. You will sit on wet rocks for lunch and kneel on sodden ground. See waterproof ratings.
• Breathability. A good 3-layer or quality 2.5-layer fabric helps on long climbs. See breathability.
• Reinforced inner ankles. Boots and crampon points scuff the lower leg; a tougher panel here extends life.
• Adjustable cuffs that close down neatly, so they don't catch on heather, rocks or crampons.
• Articulated knees for high steps and stiles.

Fell running and fast-and-light

Fell runners and fastpackers usually carry the lightest pair they can get away with, often a very packable 2.5-layer style with short ankle zips. Many fell races and mountain events set a compulsory kit list that includes waterproof trousers, sometimes specifying taped seams, and marshals may check it. Always read your event's current kit requirements rather than assuming a flimsy wind-resistant pair will pass.

Remember that ultralight trousers trade toughness for weight. They are an emergency layer: great in a rucksack, less great for a winter of daily wear.

Gaiters: with or without?

Gaiters and overtrousers do different jobs. Gaiters keep bog water, snow and wet heather out of your boot tops; overtrousers keep rain off your legs. On boggy ground many walkers wear both: gaiters on the boot, overtrousers over the gaiters so that rain running down the leg is shed onto the outside of the gaiter, not inside it.

Practical tips

• Put them on before you are wet, ideally in shelter before the rain arrives. Getting cold, soaked legs back into dry overtrousers doesn't achieve much.
• Pack them near the top of your rucksack, not under your lunch.
• On long climbs in light drizzle, open the zips to vent rather than taking them off entirely.
• If they start to feel cold and clammy even though they are not leaking, the DWR probably needs refreshing: see care & reproofing.