How to Choose a Sleeping Bag for Cold Weather Camping
By Kelty · Kelty | Published: 2026-10-21
Category: Buying Guides
Learn how to pick the right cold weather sleeping bag by understanding temperature ratings, insulation types, and fit. This guide compares Kelty models to help you stay warm and comfortable.
Quick answer
For cold weather camping, match the sleeping bag's temperature rating to the coldest night you expect, then choose insulation type based on whether you prioritize weight (down) or moisture resistance (synthetic). The Kelty Supernova 20 covers most shoulder-season trips, while the Mistral 0 handles deep winter conditions on a budget.
Temperature ratings aren’t guarantees
A bag’s EN or ISO rating shows the lower limit for a standard adult, not a comfort level. If you sleep cold, pick a bag rated 10–15°F lower than the forecast low. The Kelty Mistral 0 is rated to 0°F, ideal for nights where temperatures dip below freezing. The Supernova 20 suits milder winter trips where lows stay around 20°F.
Down insulation offers better warmth-to-weight ratio and packs smaller—great for backpacking—but loses loft when wet. Synthetic fill like CloudLoft ECO in the Mistral retains heat even damp and costs less, but is heavier and bulkier. Choose down for dry, weight-conscious trips; synthetic for wet or humid conditions or car camping.
A bag that’s too snug can compress insulation and reduce warmth, but one that’s too loose creates air pockets that let cold in. The Supernova uses a roomy shape to accommodate different body types and sleep positions without sacrificing efficiency. Narrow mummy bags save weight but may feel restrictive.
When down makes sense vs. synthetic
Down bags like the Supernova 40 (USD 101.97) are excellent for dry climates and fast-paced trips where every ounce matters. Their compact size frees up backpack space. However, in rain or high humidity, down clumps and loses insulation value unless treated with water-resistant coating.
Synthetic bags such as the Mistral 0 (USD 62.07) are more affordable and maintain warmth when damp. They dry quickly and are easier to care for. The trade-off is bulk and weight—if you’re hiking far, synthetic could fill more of your backpack.
For family car camping or base camps, synthetic’s lower price and wet-weather reliability often win. For multi-day backcountry treks in dry conditions, down is the clear choice.
Your cold-weather sleeping bag decision rules
- Check the lowest expected temperature: Look at the forecast or typical lows for your campsite. Choose a bag with a temperature rating 10–15°F below that number if you sleep cold. For a 15°F night, a 0°F bag is safer than a 20°F bag. Write down the forecast low before shopping.
- Pick insulation based on conditions: If you expect rain, snow, or high humidity, choose synthetic (like Mistral 0). For dry, cold backpacking, down (like Supernova 20) saves weight and pack space.
- Consider fit and sleeping position: Back sleepers and side sleepers benefit from a roomier cut. The Supernova’s shape accommodates various positions without overheating or creating cold spots. Mummy bags suit stomach sleepers who want minimum bulk. Lie down in the bag before buying if possible.
- Balance weight with intended transport: Car camping lets you carry a heavier synthetic bag. Backpacking requires low weight and small packed size—down bags excel here.
Compare models
- Mistral 0 Sleeping Bag: Mistral 0 uses fully recycled fabrics and CloudLoft ECO synthetic insulation with offset quilted construction. This synthetic bag keeps you warm even in damp conditions and is a budget-friendly choice for winter camping, priced at USD 62.07.
Mistral 0 Sleeping Bag - Supernova 20 Sleeping Bag: Supernova 20 uses down insulation with lofty baffles and buttery-soft recycled fabrics, plus an anti-snag zipper. Down provides excellent warmth for its weight, making this a good option for backpacking trips where temperatures drop to 20°F.
Supernova 20 Sleeping Bag
Who should choose which bag
Best for
- Campers expecting wet or humid conditions and wanting a reliable, affordable winter bag (Mistral 0)
- Backpackers who need a lightweight, packable bag for dry 20°F nights (Supernova 20)
Not for
- Extreme cold beyond -10°F—these bags are not rated for severe polar conditions
- Luxury car campers who want extra width—consider a dedicated rectangular bag
