How To Choose The Best Running Jacket

Water-resistant jackets use a durable water repellent (DWR) coating instead. Water beads up and rolls off the fabric surface. The seams aren't fully sealed, so water-resistant jackets are lighter and more breathable, but they won't hold up in sustained downpours. Choose water-resistant for drizzle and misty mornings, and waterproof when heavy or prolonged rain is likely.

A windproof jacket blocks cold gusts without the weight of a fully waterproof shell. Wind saps body heat faster than most runners expect, turning a mild day cold within minutes on an exposed route. Most windproof jackets fold down small enough to stash in a pocket or running belt, so they're easy to carry and forget about until needed.

Many windproof jackets include a degree of water resistance too, which covers you for the odd light shower without sacrificing breathability. Wind resistance combined with light water resistance makes windproof jackets a strong choice for coastal routes, exposed ridgelines, or any run where wind chill is the main threat rather than rain.

A jacket's waterproof performance comes down to its Hydrostatic Head (HH) rating. This test measures how tall a column of water the fabric can hold back before it leaks, recorded in millimetres. A 10,000mm rating means the fabric resists a 10-metre column of water before moisture gets through.

Here's what the numbers mean in practice:

The g/m²/24hr rating on the product description tells you how breathable a running jacket is. This figure measures how much moisture vapour can pass through the fabric in a day, and higher numbers mean sweat and heat escape faster, so you stay drier from the inside out.

Waterproofing and breathability pull in opposite directions. The more sealed a fabric is against rain, the harder it works to let moisture out. Most technical running jackets are breathable to some degree, though the amount varies by design and price point. Lightweight water-resistant jackets tend to breathe best because the fabric isn't fully sealed, while fully waterproof jackets need extra features, such as pit zips or laser-cut vents, to move moisture out efficiently. If you run at a high intensity or tend to overheat, prioritise breathability over maximum waterproofing.

Trail running participation in the UK has grown sharply over the past five years, with more runners heading off-road for variety and lower-impact terrain. A properly rated running jacket is one of the few pieces of kit that makes a genuine difference to how far and how comfortably you can go.

The best trail running jacket needs a waterproof rating of at least 10,000mm to 15,000mm for moderate rain, rising to 20,000mm or higher for mountain or ultra-distance routes in exposed conditions. Trail routes throw mud, wind, exposed ridgelines and sudden weather changes at you, often within the same run.

Look for membranes such as GORE-TEX or Pertex, which combine strong waterproofing with good breathability for long efforts. Ripstop nylon resists snags and scrapes from branches, rock and gorse. Many trail jackets also use hybrid construction, mixing fully waterproof panels with stretchier, more breathable fabric in high-sweat zones like the back and underarms. Hybrid construction keeps you protected without overheating on a long climb.

Insulated running jackets trap heat using synthetic or down fill, making them the right pick for frosty mornings, winter evenings, or slower-paced runs where you're generating less body heat. Synthetic insulation, such as PrimaLoft, holds warmth even when damp and dries fast, which matters on a typical British winter run. A nylon or polyester shell with a DWR coating blocks wind and light rain on top of the insulation.

A well-designed insulated jacket still breathes. Vents or panel construction let excess heat and moisture escape once you pick up the pace, so you avoid overheating even with a base layer underneath. Breathable insulation makes these jackets a better fit for runners who feel the cold quickly, rather than a default for every winter session — some runners prefer a windproof shell with extra layers instead.

A waterproof rating between 5,000mm and 10,000mm usually covers snow and light winter rain, though freezing rain or slush may call for a higher figure. Merino wool base or mid-layers add natural warmth and manage moisture well underneath a shell. Features such as body-mapped insulation, placed only where you need it, and adjustable hems and cuffs help seal warmth in without adding weight everywhere.

A packable jacket folds into its own pocket or a small pouch, so it rides easily in a running belt, backpack or race vest. These jackets aren't built for sustained heavy rain, but they're the best option for unpredictable days: a sudden shower, a windy exposed section, or a colder finish line than the start.

Ultra-light materials such as Pertex Shield keep weight down while still offering genuine weather protection. A packed-down jacket adds minimal bulk, so you'll barely notice it's there until you need it, which is why packable jackets turn up so often on race day kit lists, marathon training plans and travel trips where the forecast can shift without warning.

City runners benefit most from a 5,000mm to 10,000mm rating, lightweight polyester or nylon fabric, and strong reflective detailing for traffic and low light. A streamlined fit keeps you moving comfortably through stop-start urban routes.

Marathon trainers want lightweight versatility. A 5,000mm to 10,000mm rating covers most training runs, rising to 15,000mm if rain looks likely on race day. Minimal stretch fabric and a simple design cut down on chafing over long distances.

High-intensity and fast-paced runners need maximum airflow above all else. A rating of 5,000mm to 8,000mm is usually enough, paired with mesh panels and a minimalist athletic fit that won't flap or add drag.

• Waterproof rating suited to your typical conditions and terrain
• Breathability rating (g/m²/24hr) if you run at higher intensity
• Taped seams and water-resistant zips
• Reflective detailing for low-light safety
• Adjustable hood, cuffs and hem for a sealed fit
• Packable design if you need an emergency layer on hand

A close, athletic fit reduces drag and stops fabric flapping at pace, which suits marathon and speed sessions best. A slightly looser cut allows room for base and mid-layers underneath, which works better for winter runs or colder trail days. Try the jacket with your arms raised and moving to check it doesn't restrict your stride or shoulders.

The best running jacket depends on where and how far you run, not just the weather outside your front door. City runners need visibility and breathability. Trail and mountain runners need higher waterproof ratings and tougher fabric. Winter runners need warmth that doesn't weigh them down, and marathon trainers need something light enough to forget they're wearing.

Check the waterproof rating, the breathability figure, and the fit against your own running style before you buy.

Shop the full range of running jackets at Runners Need and get expert advice in-store if you're still deciding between options.