They say there’s no pain without gain, which is perhaps why some of the best outdoor adventures comes alongside painfully low temperatures. That’s where base layers come in. An absolute essential for mountain adventures – if you layer your base layer effectively with a good midlayer and a protective shell jacket, you’ll be adventuring all day long.
But base layers aren’t just for summiting snowy peaks. They can be a fantastic way to regulate body temperatures on a chilly morning run, or provide a layer of insulation against chilly winter winds. As the nights draw in and there’s a nip in the air once again, we’ve tested out the best base layers and selected our favourites, ready for your winter adventures.
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How To Choose A Baselayer
The biggest factors to take into account when deciding which base layer to choose are activity and environment. A trek in the high Himalayas, for example, will require a different level of insulation to what you’d need for winter trail running in the UK. Of course, there are base layers that act as great all-rounders, and we’ve tested these too.
Fit is important. To optimise warmth, make sure that you get something that fits you snugly. If your base layer is hanging off you, it will be letting lots of air in. Plus it will be trickier to layer clothing on top.
Moisture-wicking fabrics absorb very little water and draw sweat away from the body. This means that often lightweight base layers made from moisture-wicking fabric can provide much more warmth than their heavier counterparts, because they don’t retain water.
Top Base Layers for 2025 – Our favourites
From glacial walking and ice climbing right through to daily dog walks in the middle of winter, we all know we’d rather enjoy those views in comfort so, without further ado, here’s our favourite base layers for this year.
- Best Women’s Base Layer Overall: Páramo Women’s Grid Technic
- Our runner-up: BAM Sudbrook Slim Fit
- Best Merino Wool Base Layer: Howies Long-Sleeved Merino Base Layer
- Best Technical Base Layer: Megmeister Drynamo Long Sleeve
- Artilect Boulder Crew 125
- Megmeister 2 Drynamo Warm Turtleneck
- Smartwool Women’s Merino 25 Plant-Based Dye Logo Crew
- Mammut Aconcagua ML Tights