The majority of the sleeping bags on the market weigh around 1 to 2 pounds. They also come with temperature ratings that go to as low as twenty degrees F. Although they are excellent general-purpose designs that can be used in a variety of situations and backpacking excursions but they are a bit overkill in regards to weight and warmth for minimal tasks during warm summer temperatures. For this kind of weather we like our Sea to Summit Spark, which is a 12-ounce bag with a 40-degree temperature that folds into the dimensions of a one-liter Nalgene bottle. The Spark is extremely and well-rounded for its weight. It’s not like it’s counterparts, the Feathered Friends Tanager above and the Enlightened Equipment Enigma below, it is equipped with an hood and zipper and its hydrophobic down gives an excellent waterproofing feature. In all, you’d be hard-pressed to find a light, more efficient design without bumping into the 50-degree range.
However, the versatility isn’t as great in such a small bag. For a better understanding the top-rated Hummingbird has nearly twice the amount of down than the Spark that is a great addition to the cold winter evenings. Additionally it is worth noting that the Spark comes with a shorter 3/8-length zipper that allows for a bit less room to move around and restricts the amount of ventilation (the Enigma is a 40@F model). Enigma weighs 14.7 ounces. and provides a lot of versatility thanks to the quilt design). Also it is worth noting that Sea to Summit’s Sea to Summit’s 10-denier shell isn’t the smallest (the Tanager’s shell is 7 x 5D) However, it will require extra attention when you’re packing or sleeping on rough terrain. However, these flaws aside the ultra-light and ultra-compressible Spark will fit in your bike pannier or backpack more easily than any other sleeping bag which makes it an excellent option for mid-summer excursions in low altitudes.