Equipment Picks

Best Base Layer for Hiking

Best base layer for hiking

Hidden beneath the surface of a happy hiker is the perfect base layer. You can splash the cash on the very best outerwear gear but still be cold and uncomfortable because you’re not wearing a suitable base layer for hiking.

Your base layer will be the closest kept secret to a comfortable and contented adventurer, whatever the weather conditions.

Let’s look at four of the best base layers on the market. You can afford no half measures when selecting your second skin. It will keep you raring to go when others’ enjoyment levels start plummeting.

In short, the best base layers for hiking are:

  1. Icebreaker Oasis Crew Base Layer
  2. Helly Hansen Lifa Merino ½ Zip Base Layer
  3. Brass Monkeys 100% Merino Wool Base Layer
  4. Arc‘Teryx Phase Ar Zip Neck Base Layer

Each base layer has been tested and analysed based on its ability to control body temperature, ability to wick, level of breathability, comfort and design.

There are lots of base layers out there and finding the right one for the conditions you will most be hiking in is crucial for you to get the maximum joy out of your hiking experiences.

We pride ourselves in giving you honest and clear information so you will be able to spend less time looking for the perfect base layer and more time wearing it.

Icebreaker Men’s Oasis Long Sleeve Crewe Base Layer

Bragging rights:

  • Lightweight
  • Breathable
  • Outer fabric 100% Merino wool
  • Underarm gussets improve range of motion
  • Offset shoulder seams prevent pack rub
  • Flatlock seams prevent chafing
  • Drop-tail hem
  • Crewe neck
  • Machine washable

Some amazing things have come out of New Zealand; Bungee Jumping… Jogging… the Jet Pack … and the Icebreaker brand!

Icebreaker was made with outdoor adventure in mind and you can tell why as soon as you pull on this base layer.

It’s great for hiking in all year round, it wicks away sweat and can still keep you warm if you end up hiking in temperatures as low as 0⁰C.

Constructed of 100% merino wool means that this lightweight base layer not only has high breathability and natural odour resistance but provides core body temperature stability, thus lowering your heart rate and helping you go that extra mile!

Related: Is Merino Wool better than Synthetic for your Base Layer?

It’s designed with comfort in mind too – a nice fit and no irritation or chafing even when worn for long periods of time.

A drop-tail hem provides additional protection and comfort. For an all-round base layer, you’ve got a dealbreaker with the Icebreaker Oasis.

The Oasis comes in a limited number of muted colours, so no standing out like a Belisha beacon on your hike with this garment.

If you like using bright colours for high visibility purposes, you can add brighter layers on top.

The brilliant 100% merino wool along with practical design features, make this an essential purchase. It’s a base layer that will keep you comfortable and happy on the hill for years to come.

Helly Hansen Lifa Merino ½ Zip Base Layer Longsleeve T-shirt

Bragging rights:

  • Lightweight,
  • Breathable
  • Quick dry
  • Flatlock seams
  • 100% merino exterior layer
  • Lifa Flow Stay Warm Technology interior layer; (57% merino wool 43% Polypropylene)
  • Machine washable

Helly Hansen have been at the cutting edge of professional outdoor wear since 1877 and have come up trumps with this double-layered base layer. The technology they use, mixing a layer of merino wool and a layer of their Lifa Flow stay-dry fabric ensures that you will feel unbelievably warm, dry and comfortable for as long as you are out on any harsh hiking trails.

Related: What is the point of a base layer?

This base layer is for when you are serious about hiking regardless of a drop in the mercury. This is their warmest base layer and a sure winner if you are hiking in cold conditions.

Sub-zero is a walk in the park.

It feels soft against your skin, but obviously not as soft as if you had 100% Merino. However, the benefits of having that added durable, super-fast drying synthetic layer have been hailed by Helly Hansen for 40 years and echoed across the hills and mountains by many a hiker.

The attention to detail is superb, with flatlock seams that cause no chaffing, ½ zip opening, colours galore and designs that make you stand out from the crowd so that you will feel good stripping down to your base layer if weather conditions permit.

A great piece of kit for when you need extra protection from the colder climes and would certainly be our winner when you are hiking in such conditions.

Brass Monkeys 100% Merino Wool Base Layer

Bragging rights:

  • 100% merino wool
  • Naturally breathable
  • High wicking ability
  • Extra soft and warm,
  • No itch
  • Odour resistant
  • Natural antibacterial properties
  • Crew neck
  • Shaped tail
  • Machine washable

Advertised as a base layer ‘for ultimate comfort and warmth all year round’ you won’t be disappointed by Brass Monkeys’ claims.

Its design is perfect for warmth without the bulk, and what’s more, with its breathable and high wicking natural fabric you’ll not become overly hot and sweaty.

With a crew neck, shaped tail and long sleeves it gives you extra cover for when you don’t want to take cover.

It’s a beautiful slim fit in a huge range of sizes so you are sure to get the size that fits you like a base layer should- tight enough to feel like a second skin but with enough room to allow you to manoeuvre.

Made from 215gm merino wool fabric, this is a base layer that is super-soft and so comfortable you might convince yourself you won’t need to take it off at all!

Not such an outlandish idea when you consider that because it is made of 100% merino wool, it is odour resistant and has antibacterial properties! So, for times when you can’t just step into the shower for a while, you won’t need to keep your distance from your fellow adventurers!

Another reason why this Brass Monkeys base layer is a great buy is that it is made from ethically farmed New Zealand merino wool, meaning that on your hikes, you can look any sheep you pass straight in the eye, conscience free.

Arc’Teryx Men’s Phase Ar Zip Neck Base Layer

Bragging rights:

  • Lightweight
  • Anatomical shaping
  • Breathable
  • Deep zip
  • 100% polyester
  • Quick-dry moisture management
  • Silver ion antibacterial treatment for odour resistance
  • Performance stretch
  • Flatlock seams preventing chafing
  • Machine washable

I’ve included this base layer for those who want to go 100% merino free. Undoubtedly merino has its advantages but even though it’s superfine and non-itchy, there are those out there who are allergic to natural wool fibres and so need a reliable synthetic option.

Or you might prefer the benefits of having a fabric that dries more quickly. Whatever the reason, if you want a great synthetic all-rounder that is super comfortable to wear, then this is it!

The fabric has a soft touch and has the benefit of having good breathability, moisture-wicking, and is warm enough to wear in cooler temperatures.

The high collar neckline with a deep zip, not only looks good but is a versatile touch that will provide extra protection from the cold on your Autumn and Winter hikes.

Additionally, it can be washed over and over adding to its long term appeal.

The downside is that even though silver ion antibacterial treatment works well on an average hike it does pick up odours after an arduous day on the hill – it still requires regular washing!

Tips When Choosing a Base Layer for Hiking

Base layers are an important part of your kit if you are a serious hiker. Choose a base layer that has good breathability and wicks moisture well – it’s so important for regulating your body temperature, and in extreme cold, can even save your life.

Comfort is another essential aspect, therefore look for good quality natural merino wool or well-engineered synthetic fabric. Comfort also comes from flatlock seams and products that are designed to fit snugly but give you freedom of movement. The last thing you want is to feel constrained.

Related: Learn why you need lightweight hiking trousers here.

Bear in mind what weather conditions you are going to hike in. If you are hiking in the Lake District in Spring you are going to want a more lightweight fabric than if you are going hiking in the Outer Hebrides in Winter.

But sometimes it’s not as simple as that, the morning and evening temperatures can feel like a different weather zone to afternoon temperatures. Consequently, choose multiple layers where your base layer is something that would work as an only layer too. That’s where looking as well as feeling cool come into the equation.

Parting thoughts

For more tips and explanations on base layers (from a Rab perspective), check out their guide here.

The Icebreaker Oasis is the best all-rounder. It’s got everything you need for the conditions most hikers are going to face. Comfort, breathability and all the benefits of being made with 100% merino wool gives this base layer our number one position.

If you were going to experience colder climes, choose the Helly Hansen Lifa-Merino base layer. It’s designed with a combination of natural and scientifically developed fibres giving you the best of both worlds when you are facing harsher conditions.

For those who prioritise sustainability, Brass Monkeys weren’t monkeying around when they came up with their Brass Monkeys base layer! 100% ethically farmed merino wool it’s another all-rounder that doesn’t let you or the environment down.

Finally, if you are looking for a synthetic, fast-drying, non-wool base layer then Arc’Teryx Phase Ar is the one for you. Breathable, able to wick and with features that make this a comfortable garment to wear, are all reasons why we’ve rated this in the top four of the best base layers for hiking.

I hope this has been helpful.

See you on the mountain.