Best Sea to Summit Mummy Sleeping Bags of 2025

The Spark Pro Sleeping Bag offers exceptional warmth with its 950+ fill power, RDS-certified goose down, ensuring you stay cosy even in damp conditions thanks to its Ultra Dry Down treatment. Its lightweight 10-Denier Nylon shell provides breathability and effective temperature regulation, enhancing your outdoor comfort. With a mummy fit design, it maximises thermal efficiency while minimising bulk, making it ideal for ultralight backpacking. The innovative Free Flow Zip System allows for easy access and ventilation, ensuring a comfortable night’s sleep.

The SEA TO SUMMIT Spark Sleeping Bag is a lightweight and compact option designed for your spring and summer adventures. With its technical design, the generous footbox and hood maximise thermal efficiency, keeping you warm during cooler nights. The premium 850+ Loft Ultra-Dry Down insulation provides excellent warmth while remaining comfortable, even in damp conditions. Additionally, the ultralight weight of just 536g means you can easily carry it on your backpacking trips without sacrificing space or comfort.

The SEA TO SUMMIT Spark Bag is engineered specifically for women, featuring a tailored design that offers enhanced warmth and heat retention. With its premium Ultra-Dry Goose Down insulation, this sleeping bag guarantees a fantastic warmth-to-weight ratio, ensuring you stay comfortable on cooler nights. Weighing only 584g, it is ultra-light and easy to carry, making it perfect for backpacking or bikepacking trips. Additionally, the compact design allows you to pack it down easily, so you can focus on your adventures without the bulk.

The Ascent AcII-R Sleeping Bag by Sea to Summit is designed for adults and is perfect for mountaineering and trekking. Weighing just 1.361 kilograms, it is lightweight and easy to carry, making it a convenient choice for your outdoor adventures. Its mummy shape provides excellent insulation and warmth, ensuring you stay comfortable during chilly nights. With dimensions of 20.32 L x 45.72 H x 33.02 W centimetres, it is compact enough to fit into your gear without taking up too much space.

The Sea to Summit Spark SpIII is an excellent choice for those seeking warmth and comfort during outdoor adventures. Its down treatment ensures maximum insulation, keeping you cosy even in cooler conditions. The contoured mummy shape is designed to efficiently trap warmth, ensuring you stay snug all night long. This sleeping bag is ideal for camping, backpacking, or any outdoor activity where light weight and warmth are essential. With the Spark SpIII, you can enjoy restful nights under the stars.

The Sea to Summit ThII Sleeping Bag features innovative WaveLoft construction, which enhances air-trapping to keep you warm during your adventures. Its quality DWR-treated nylon shell repels moisture, ensuring you stay dry even in damp conditions. The comfortable 20D nylon liner fabric adds to your sleeping comfort, making for a restful night. Additionally, the full-length YKK zip allows for increased ventilation and versatility, enabling you to use the bag as a quilt or comforter when needed.

The SEA TO SUMMIT Down Sleeping Bag is designed specifically for women, featuring a tailored shape for enhanced warmth and comfort. With premium 650+ Loft Ultra-Dry Duck Down insulation, you can expect superior heat retention, perfect for chilly nights. It is rated to -1°C, making it ideal for unpredictable weather conditions. Plus, its compact and lightweight design allows for easy packing and transport, ensuring you can enjoy your adventures without the bulk of heavy gear.

The Trailhead ThII R Sleeping Bag offers impressive features for a comfortable night's sleep outdoors. Its insulation material is bonded to the outer layer, preventing any shifting, which ensures you stay warm throughout the night. The zip channel includes an anti-snap design, providing hassle-free access. Additionally, the WaveLoft construction combined with synthetic insulation enhances warmth and bulk, making it an excellent choice for chilly conditions. This sleeping bag is designed to keep you cosy and secure, so you can enjoy your adventures worry-free.

The EMBER EbII R Sleeping Bag features an ultra-light 10D outer and 7D inner material, making it easy to carry and pack away. It is filled with RDS certified 850+ Loft Premium Goose ULTRA-DRY Down, providing excellent insulation to keep you warm in chilly conditions. With versatile adjustment options, you can easily adapt the bag for various weather scenarios. Additionally, two EMBER bags can be linked together, allowing you to create a spacious double blanket for a more comfortable sleep experience.

The SEA TO SUMMIT Down Sleeping Bag is specifically engineered for women, providing extra insulation in key areas for enhanced warmth and comfort during chilly nights. With its premium 650+ Loft Ultra-Dry Duck Down filling, you can enjoy superior warmth and durability. Rated to -9°C, this bag is ideal for three-season use, ensuring you stay cosy even in unpredictable weather. Additionally, the compact design allows you to easily pack it down for trekking or camping, making it a perfect travel companion.