Be sure to look at our guides to outdoor gear, like the Best Day-Hiking Packs, Best Tents, Best Sleeping Bags, Best Backpacking Sleeping Pads, Best Rain Jackets, Best Backpacking Water Filters, Best Merino Wool, and Best Binoculars. Check out our guides to the Best Sleeping Bags and the Best Backpacking Sleeping Pads. Photograph: Scott GilbertsonREI Co-op's Magma 15 is our favorite bag for shoulder-season trips when the temps might drop more than expected. Nemo's Forte 20 is a 20-degree synthetic-fill sleeping bag, but the comfort rating is 30 degrees. I did wear some merino base layers and a wool hat, but sleeping bag comfort ratings assume this.