Last updated: November 2026
For winter camping, bivouacs, and alpine tours, you need a sleeping bag that truly keeps you warm — the wrong model can be dangerous. This guide explains the most important metrics and helps you find the right winter sleeping bag for your needs.
Understanding temperature ratings correctly
All European sleeping bags are tested according to the EN ISO 23537 standard (successor to EN 13537). The three most important values are:
| Value | Meaning | For whom? |
|---|---|---|
| Comfort temperature | A standard female sleeps comfortably | Standard sleepers |
| Limit temperature | A man sleeps without freezing | Warm sleepers |
| Extreme temperature | Survival rating — no comfort | Emergencies only |
Rule of thumb: Always buy a sleeping bag rated 5°C colder than your expected minimum temperature.
Down vs. synthetic insulation — which is warmer in winter?
| Property | Down | Synthetic |
|---|---|---|
| Warmth-to-weight ratio | ★★★★★ | ★★★☆☆ |
| Pack size | ★★★★★ | ★★★☆☆ |
| Water resistance | ★★☆☆☆ | ★★★★☆ |
| Lifespan | ★★★★★ | ★★★☆☆ |
| Price | Higher | More affordable |
Winter recommendation: Down with at least 700 cuin (fill power) for light tours, 800+ cuin for extreme conditions. In damp conditions (cave bivouacs, heavy sweating): synthetic insulation.
Mummy or rectangular sleeping bag?
For winter, the choice is clear: a mummy sleeping bag. The snug fit prevents cold air pockets and saves up to 30% in weight compared to a rectangular sleeping bag of the same warmth. The hood section is indispensable in winter.
Buying recommendations by use case
- Autumn trekking (0°C to −5°C): Comfort temperature −5°C, 700 cuin down, ~800g
- Winter camping (−10°C to −15°C): Comfort temperature −15°C, 800 cuin, ~1,200g
- Alpine tours / extreme winter: Expedition sleeping bag −25°C+, 900 cuin, 1,500g+
- Winter hut stays: Comfort temperature of −5°C is usually sufficient, choose a lightweight model
Sleeping bag for −10 or −20 degrees – what do you really need?
The number in the product name is almost always the limit temperature, not the comfort temperature. A "−10 degree sleeping bag" will therefore often only keep you truly warm down to about −5 °C. Plan as follows:
- Sleeping bag down to minus 10 degrees: For winter camping in low mountain ranges and foothills, and for late autumn bivouacs. Pay attention to a comfort temperature around −10 °C, not just the limit.
- Sleeping bag down to minus 20 degrees: For mid-winter nights above 2,000 m or in Scandinavia. Look for a comfort temperature around −15 °C to −20 °C, high fill power, and a draft collar.
- Colder than −20 degrees: Expedition sleeping bags. For normal winter tours, they are too heavy and too warm.
With warm, dry merino base layers and a beanie, you can noticeably gain a few extra degrees of warmth in your sleeping bag.
Sleeping pads in winter: No warm sleep without the right R-value
The best winter sleeping bag won't help much if the frozen ground drains your heat from below. The down underneath you gets compressed and provides little insulation. This job is handled by the sleeping pad, measured by its R-value (ASTM F3340): the higher the value, the better the insulation.
- R-value 2–3: Summer and warm shoulder seasons
- R-value 4–5: Three seasons down to light frost; winter with snow only when paired with a second pad
- R-value 5+: Winter on snow and frozen ground
Tip: R-values can be added together. A foam pad underneath an air pad increases insulation and protects against punctures.
Our winter recommendations




You can find all models under down sleeping bags and sleeping pads.
Care & storage — how to make your sleeping bag last forever
- Do not store rolled up — always keep it loosely packed in a large storage sack
- Down: Wash only with special down detergent at 30°C, tumble dry with tennis balls
- Air out thoroughly after every tour — never pack it away damp
- Use a sleeping bag liner → significantly extends the time between washes
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