12 Best Base Layers for Hiking UK: Expert-Tested Picks 2025

If your hikes swing between sweaty climbs and chilly ridgelines, the wrong base layer turns a good day out into a stop–start faff. Cotton gets clammy, heavy fleeces overheat, and even “technical” tops can leave you shivering when the wind picks up. In the UK—where a blue-sky start can end in sideways rain—your next-to-skin layer is the bit that keeps you dry, regulates heat, and staves off that damp chill that creeps in at lunch stops and summits.

This guide rounds up the 12 best base layers for hiking in the UK for 2025, all tested and compared for real British conditions. You’ll find clear picks for winter Munros, shoulder-season scrambles, and hot-weather hill days—plus whether to go merino, synthetic or hybrid, what fabric weights actually mean, and which features matter (zips, hoods, thumb loops, odour control, sustainability). We’ve included UK prices and trusted places to buy. Ready to sort your layering once and for all? First up, our editors’ pick: Fjällräven’s Abisko Day Hike LS.

1. Fjällräven Abisko Day Hike LS (Take a Hike UK editors’ pick)

If you want one top to cover most UK hill days, this is it. The Abisko Day Hike LS is featherlight, dries fast between showers and snack stops, and feels so comfortable you forget about it. It’s the all-rounder our team reached for most in 2024–25 testing.

Best for

Three-season UK hiking and backpacking where you need reliable moisture management without bulk. Ideal for shoulder-season scrambles, breezy ridge days and as a daily go-to on multi-day trips.

Fabric and weight

Made from 88% recycled polyester and 12% polyester, it’s a wicking, quick-drying knit that balances airflow with next-to-skin comfort. Weight is a scant 164g in men’s M, keeping pack weight down on longer routes.

Key features

A stripped-back design keeps the focus on performance and comfort rather than gimmicks. In use it excels at moving sweat and drying quickly during changeable UK conditions.

• Lightweight and fast-drying: Sheds sweat and drizzle swiftly.
• All-round comfort: Soft handle; you barely notice it on skin.
• Versatile sleeve options: Available in long sleeve and short sleeve.
• Everyday styling: Looks good from car park to café.

Fit and sizing

Regular fit with a little room for airflow without feeling baggy. True to size and easy to layer under a fleece or shell. Available in men’s and women’s versions, sizes XS–XXL.

UK price and where to buy

RRP £75. Commonly stocked by Fjällräven UK and major outdoor retailers nationwide; expect periodic colour-way discounts.

Considerations

The long-sleeve version isn’t the most breathable choice for peak summer heat—opt for the short sleeve then. It’s also intentionally low on bells and whistles, and you’ll want a warmer layer underneath or over it for deep winter days.

2. Artilect Flatiron 185 Crew

A premium technical merino that genuinely balances warmth and airflow, the Flatiron 185 kept us cosy on blustery Peak District edges yet never clammy on the climb. If you want a high-performance layer that works hard across mixed UK conditions, this is a standout.

Best for

Cold-to-cool UK hill days, scrambles and fast hiking where you need a warm-for-weight layer that still breathes on the move. A top pick among the best base layers for hiking in the UK when temperatures yo-yo.

Fabric and weight

91% merino wool with 9% nylon for strength; zoned ventilation panels run from sleeves through the underarm and torso. It weighs 177g (women’s), impressive given the warmth on offer.

Key features

Built to run warm without the swampy feel of heavier knits, with thoughtful mountain-focused details.

• Warm-for-weight merino: Stays cosy in wind without bulk.
• Zoned venting: Wide mesh-like panels boost breathability.
• Thumb loops & long cut: Locks in heat; great under shells.
• Flat seams: Layers cleanly and resists chafe under a pack.
• Movement-friendly: Hem doesn’t ride up when you reach.

Fit and sizing

Snug, performance fit with a longer hem. Soft next-to-skin, non-itchy. If you prefer a relaxed feel, try before you buy or consider sizing up. Available in men’s XS–XXL and women’s XS–XL.

UK price and where to buy

RRP £110, commonly seen around £100 at UK outdoor retailers. Widely available in both men’s and women’s versions.

Considerations

The close fit won’t suit everyone, and the premium price reflects its merino content. Like most merino, it’s not as hard-wearing as pure synthetics and can feel warm on the hottest summer days.

3. Craghoppers NosiLife Abel long sleeved T-shirt

A wallet-friendly, do‑it‑all layer for UK trails, the NosiLife Abel punches above its price. It’s technical without fuss, breathes well on warm climbs, and brings rare built‑in insect defence for Scottish midsummer or lowland marshes. One of the best base layers for hiking in the UK if value matters.

Best for

Day hikes and travel in spring to autumn, especially midgey or mozzie‑prone areas. A dependable everyday hiking tee that doubles for casual wear.

Fabric and weight

75% recycled polyester, 22% organic cotton, 4% elastane. The blend feels soft and a touch stretchy, with good airflow. Claimed weight around 204g (long sleeve).

Key features

• NosiLife insect repellent: Factory-applied treatment designed to last the product’s lifespan.
• Anti‑odour finish: Stays fresher on multi‑day trips.
• Breathable knit: Comfortable in heat yet offers decent warmth when temps dip.
• Understated styling: Trail to town friendly.

Fit and sizing

A regular, not‑too‑tight cut that layers easily and moves well. Men’s sizes typically S–XXXL; women’s equivalent is the NosiLife Akona.

UK price and where to buy

RRP £45. Widely available via Craghoppers UK and major outdoor retailers; frequent deals make it an easy win.

Considerations

Feature‑light (no zip/hood or thumb loops). Not a winter specialist—pair with a warmer mid‑layer in cold snaps. The cotton content prioritises comfort over outright fast‑drying speed of pure synthetics.

4. Rab Rivelin Hoody

A breathable, hooded synthetic that shines from fast hikes to scramble days, the Rivelin Hoody wicks hard, dries fast and adds just‑enough weather protection with its soft, low‑profile hood. It’s a versatile pick among the best base layers for hiking in the UK when you want airflow plus a little extra coverage.

Best for

Shoulder‑season UK hill days, breezy ridgelines and stop‑start efforts where quick drying and a protective hood beat outright insulation. Doubles as a light mid‑layer in milder weather.

Fabric and weight

Rab Dryflo main fabric with mesh underarm inserts; 83% recycled polyester, 12% lyocell, 5% elastane. Claimed weight 294g (men’s). High‑wicking, quick‑drying and soft next to skin.

Key features

• Airflow focused: Mesh underarm panels boost breathability.
• Protective hood: Soft, stretchy hood for extra warmth and wind cover.
• Stay-put sleeves: Discreet elasticated thumb loops prevent ride‑up.
• Comfort-first build: Smooth, soft handle that layers cleanly under a shell.
• Versatile use: Works as base or light mid on warmer days.

Fit and sizing

Loose and stretchy without feeling baggy; easy to move in under a pack or shell. Men’s sizes S–XXL, with a women’s version available.

UK price and where to buy

RRP £60. Commonly stocked by Rab and major UK outdoor retailers; regular discounts pop up through the year.

Considerations

Not the warmest option—add a warmer mid‑layer for winter cold snaps. At 294g it’s heavier than ultra‑light baselayers, and the hood under a close‑fitting collar won’t suit everyone.

5. Helly Hansen Lifa Merino Midweight Half-Zip

When winter bites, this hybrid merino layer is a heater. The Lifa Merino Midweight combines Helly Hansen’s fast‑wicking polypropylene next to skin with warm, odour‑resistant merino outside. On test it stayed toasty under a shell on sub‑zero mountain days and kept pace when working hard uphill.

Best for

Cold and sub‑zero UK hikes where you need dependable warmth that still wicks during active use. A winter go‑to among the best base layers for hiking in the UK.

Fabric and weight

Two‑layer LIFA construction: 57% ZQ‑certified merino wool (outer) and 43% polypropylene (liner) for superior moisture management with merino comfort. Claimed weight around 390g.

Key features

• Serious cold‑weather warmth: Reliable under a shell in freezing conditions.
• Excellent wicking: Polypropylene liner pulls sweat fast.
• Soft, non‑itch merino: Comfortable all day.
• Half‑zip collar: Adds neck protection and on‑the‑move venting.
• Durable build: Holds shape and feel after repeated washes.

Fit and sizing

A good, athletic cut—neither baggy nor sprayed‑on. Testers wanted a touch more length in sleeves and body for full coverage during dynamic movement. No thumb loops. Men’s S–2XL; women’s XS–XL.

UK price and where to buy

RRP £90. Widely available in the UK in men’s and women’s versions from Helly Hansen and mainstream outdoor retailers.

Considerations

No thumb loops and the neck zip isn’t especially deep for dumping heat. Best saved for cold conditions—can feel warm if temperatures rise. Heavier than ultralight baselayers.

6. Peak Performance Freelight Polartec Power Grid Crew

Think of this as a thin, technical fleece you can wear next-to-skin. The Freelight’s Polartec Power Grid interior moves sweat fast while trapping just enough warmth, making it a superb choice for cold, stop–start UK hill days where many layers feel fussy.

Best for

Strenuous hiking and scrambling in cool to cold conditions, or as a light mid-layer year-round. Among the best base layers for hiking in the UK when you run warm but still need insulation.

Fabric and weight

Polartec Power Grid with a high-wicking, grid-knit interior. Fabric composition is 94% polyamide and 6% elastane. Claimed weight is a very light 155g.

Key features

Built for active warmth with practical, everyday usability.

• Grid fleece interior: Channels sweat away and boosts airflow.
• Warm yet breathable: Keeps you in the “not too hot” zone on climbs.
• Zipped chest pocket: Handy for ski passes or small essentials.
• Elasticated hem: Helps seal in warmth and tidy the fit.
• Smooth face fabric: Slides cleanly under shells.

Fit and sizing

Relaxed, layer-friendly cut; easy to pull over a skin-tight tee or wear solo. Men’s S–2XL and women’s XS–XL.

UK price and where to buy

RRP £150. Available in men’s and women’s versions from mainstream UK outdoor retailers; occasional colour-dependent discounts appear seasonally.

Considerations

Runs warm for high-summer walking. Pricey versus simpler synthetics, and while it works as a base, many will treat it as a light mid-layer in milder weather.

7. Woolpower Zip Turtleneck 200

When the mercury drops and the wind bites, this unisex merino-rich layer is a proper winter workhorse. The Zip Turtleneck 200 brings pub‑fire warmth without giving up on breathability, making it a solid cold‑season choice among the best base layers for hiking in the UK.

Best for

Cold to sub‑zero UK hikes, winter hill days and hut trips where reliable next‑to‑skin warmth is the priority, with enough venting from a zip neck for steep climbs.

Fabric and weight

Ullfrotté Original 200, the brand’s lightest knit: 60% merino wool, 25% polyester, 13% polyamide, 2% elastane. Claimed weight 260g, balancing insulation with airflow.

Key features

• Serious warmth: Fine merino blend traps heat yet doesn’t swamp.
• Zip turtleneck: Easy ventilation and extra neck protection.
• Breathable knit: Ullfrotté 200 promotes airflow to dump excess heat.
• Soft, stretchy handle: Comfortable against skin on long days.
• Drop-tail hem: Longer back helps prevent ride‑up under a pack.

Fit and sizing

Close‑fitting, torso‑hugging cut designed to layer cleanly and stay put; longer rear hem aids coverage. Unisex sizing from XXS–XXXL—check measurements if you prefer a relaxed fit or want room for a thin tee beneath.

UK price and where to buy

RRP £120. Commonly available in the UK from established outdoor retailers in a full size run.

Considerations

Runs warm—overkill for summer and mild spring days. The close fit won’t suit everyone, and at 260g it’s heavier than ultralight synthetics. As with most merino‑based pieces, treat it well to maximise long‑term durability.

8. Jack Wolfskin Vonnan LS

A simple, good‑value layer that just works, the Vonnan LS is light, fast‑drying and stays fresher than most synthetics. For milder UK days when you want moisture management without bulk, it’s an easy pick among the best base layers for hiking in the UK.

Best for

Spring to autumn hill days, brisk coastal paths and run‑hike commutes where you’d rather keep things light, breathable and low‑maintenance.

Fabric and weight

100% polyester (made from recycled materials). It isn’t as plush or stretchy as merino, but it’s comfortable on skin and dries quickly. Claimed weight is a feathery 138g, great for multi‑day packing.

Key features

• Reliable wicking: Moves sweat well and avoids that muggy feel.
• Anti‑odour treatment: Stays surprisingly fresh after hard use.
• Fast drying: Ideal for stop–start UK weather and travel.
• Ultralight packability: Disappears in the rucksack.
• Straightforward design: Crew neck, no faff.

Fit and sizing

Not skin‑tight; the regular cut allows a touch of airflow without going baggy. True to size. Women’s XS–2XL and men’s S–2XL versions available.

UK price and where to buy

RRP £40. Widely stocked by Jack Wolfskin UK and nationwide outdoor retailers, with frequent promo pricing.

Considerations

Not a cold‑weather specialist—add a warmer mid‑layer for winter. Feature‑light (no zip, hood or thumb loops). Hand‑feel and stretch aren’t on par with merino, though the trade‑off is price and durability.

9. Helly Hansen Shine Solen Half-Zip Sun Hoodie

A hot‑weather specialist built for exposed UK trails, the Shine Solen is the sun hoodie you wear when there’s little shade and lots of mileage. It guards skin with UPF 50 fabric, vents well via a long half‑zip, and dries quickly enough between sweaty climbs and sea‑breeze descents.

Best for

High‑UV summer hiking and trail runs on exposed ridges, coastal paths and mountain plateaus. A top warm‑weather pick among the best base layers for hiking in the UK.

Fabric and weight

80% recycled polyamide, 20% elastane; light, stretchy and cool to the touch. Claimed weight 191g.

Key features

• UPF 50 sun protection: Reliable coverage for long, exposed days.
• Half‑zip ventilation: Dump heat fast when the pace rises.
• Functional hood: Lightweight with a ponytail slot for tidy coverage.
• Thumb loops: Keep sleeves anchored and protect backs of hands.
• Quick drying: Sheds sweat and light showers between efforts.

Fit and sizing

Relaxed, airy cut with a “drafty” feel that helps in the heat. Easy to open up at the neck for extra airflow. Women’s XS–XL; men’s S–2XL.

UK price and where to buy

RRP £70, frequently discounted to around £49 in the UK. Widely available in both men’s and women’s versions.

Considerations

No anti‑odour treatment, so it can pick up smells on multi‑day trips. Wicks reasonably but can feel a touch clammy on very humid days. Usage is largely summer‑focused; you’ll want warmer layers once temperatures drop.

10. Rab Syncrino Base LS Tee

A soft, odour‑resistant merino blend with a relaxed cut, the Syncrino Base LS Tee is the long‑sleeve you can wear day after day without a stink. It breathes well, dries reasonably quickly and feels great next to skin—ideal if you like a tee‑style base rather than a tight technical top among the best base layers for hiking in the UK.

Best for

Mild to cool UK hill days, spring and autumn walks, and multi‑day trips where odour control matters. Works equally well as a standalone long‑sleeve or under a light mid‑layer.

Fabric and weight

Syncrino 125 merino blend: 52% partially recycled polyester, 47% merino wool. Around 125gsm with a claimed garment weight of 170g, offering more warmth than similar‑weight pure synthetics.

Key features

• Odour resistance: Merino content stays fresh over multiple days.
• Comfort next to skin: Minimal itch; soft, smooth handle.
• Low‑profile seams: Sensible placement for pack comfort.
• Dries reasonably fast: Wicks well; sheds moisture between efforts.
• Ethical creds: Rab holds Fair Wear Foundation ‘Leader’ status.

Fit and sizing

Fairly relaxed, versatile cut with nice long sleeves and body for coverage. Crew neck. No thumb loops. Men’s S–2XL; women’s 8–16. True to size; size up only if you want a looser, T‑shirt feel.

UK price and where to buy

RRP £65, often discounted to about £58–£60 at major UK outdoor retailers. Available in men’s and women’s versions.

Considerations

Not the warmest option for winter—add a beefier mid‑layer when it’s Baltic. No thumb loops, and you may notice some dampness under pack contact points before it dries. Crew neck leaves the nape exposed on windy tops.

11. BAM 200 long sleeve (bamboo)

Prefer a wool‑free option? BAM’s bamboo long sleeve is a soft, breathable alternative that’s kind to skin and easy to wear all day. For UK trails from spring into autumn, it offers reliable moisture management, natural odour resistance and a comfy, midweight feel that slots neatly into most layering systems.

Best for

Mild to cool UK hikes, travel and multi‑day trips where comfort and odour control matter. A great pick if merino itches or you want a more sustainable fibre among the best base layers for hiking in the UK.

Fabric and weight

Bamboo‑based fabric typically blended with fibres like cotton and elastane to enhance durability, stretch and shape retention. Bamboo is softer than cotton, wicks well and delivers good warmth for weight.

Key features

Built for everyday comfort with performance that suits British shoulder seasons.

• Super‑soft handle: Gentle next to sensitive skin.
• Moisture management: Wicks effectively to keep you comfortable.
• Odour resistance: Stays fresher over repeat wears.
• Sustainability upside: Fast‑growing fibre with lower resource demands than merino or petrochemical synthetics.
• Shape retention: Blends hold their form over time.

Fit and sizing

Best worn as a close, next‑to‑skin layer without being compressive. Blended elastane typically adds easy stretch. Check the brand’s size chart if you prefer a roomier tee‑style fit.

UK price and where to buy

Available in the UK from the brand and mainstream outdoor stockists; pricing varies by season and colourway.

Considerations

Not a deep‑winter specialist on its own—pair with a warmer mid‑layer in cold snaps. For sweat‑heavy days where the fastest dry time is critical, lightweight synthetics often have the edge.

12. Icebreaker 200 Oasis long sleeve crewe

Icebreaker’s classic merino crew is the benchmark “do-everything” baselayer: warm for its weight, naturally odour‑resistant and reliably comfortable next to skin. For UK hills it’s an easy, year‑round staple—fine on its own in cool shoulder seasons, and superb under a fleece or shell when winter weather closes in—earning its place among the best base layers for hiking in the UK.

Best for

Three‑season hiking and winter layering when you want consistent comfort, scent control and simple, fuss‑free performance.

Fabric and weight

Midweight merino knit (around the 200gsm sweet spot): breathable, temperature‑regulating and naturally odour resistant, as highlighted in expert merino guidance.

Key features

• Merino performance: Balances warmth and breathability across changing conditions.
• Odour resistance: Wear for multiple days without stink on backpacking trips.
• Low‑profile seams: Designed to sit comfortably under pack straps.
• Crew simplicity: No zip to bunch; layers cleanly under fleeces and shells.
• Year‑round versatility: Solo in cool weather, or as a winter first layer.

Fit and sizing

A close, next‑to‑skin athletic fit that moves with you without feeling restrictive. Available in men’s and women’s cuts across a broad size range; choose true to size for classic baselayer fit.

UK price and where to buy

Sits in the premium merino bracket and is widely available from major UK outdoor retailers in multiple colours and sizes.

Considerations

Merino dries more slowly and is generally less abrasion‑resistant than pure synthetics, so treat it kindly. Not the coolest choice for hot, humid summer ascents; switch to a lightweight synthetic sun top when temperatures spike.

Final thoughts

Pick your base by the day you’ve planned: synthetics for sweaty climbs and fast dry times, merino or merino‑hybrids for cold snaps and multi‑day odour control, grid fleeces when you’re working hard in winter, and a sun hoodie when the UV is high. Prioritise fit (close but not tight), seam comfort and the right fabric weight. Then let your mid‑layer and shell do the rest of the heavy lifting when the weather turns.

Ready to upgrade your layering? Explore our editors’ picks and build a dependable system with free UK delivery over £50, easy 14‑day returns and helpful support, all at Take a Hike UK. See you on the trail.