To make sure your jacket can keep you warm in cold weather, here's what to look for when you shop:
✔️ Insulation type: Your two main choices are down and down alternative (i.e. polyester):
Down offers the best insulation because its clusters trap in heat. Keep in mind that down is not the same thing as feathers. Down comes from the undercoat of ducks or geese, while feathers are a protective covering on their outer layer. Sometimes a coat's insulation is a blend of down and feathers, which helps keep the cost lower, but feathers aren't as lofty. Many brands have worked to improve the traceability of their supply chains and ensure the birds are not force-fed or live-plucked. Look for certifications like the Responsible Down Standard (RDS) to ensure the down complies with these practices.Down alternative is better if you're on a budget or prefer an animal-free option. Synthetic fibers like polyester are created to mimic down clusters. While they're often less expensive and may be easier to clean, down alternative fills may not be as lofty as real down. For less of an environmental impact, you can often find down alternative fills that are made from recycled plastic.
✔️ Fill power: This term specifically applies to down insulation (though some down alternative products list their fill power equivalent). In technical terms, it tells you the volume of the down in cubic inches per ounce. In real-life terms, it lets you know how warm and cozy the coat will feel. A higher number means the down takes up more space and traps more air for better insulation.
Fill powers can range from 300 to 900, but anything over 550 is considered warm. Just keep in mind that this isn't the same thing as fill weight, which tells you how much down is actually used. You can find a lightweight winter jacket with a high fill power that has good insulating properties, but can't keep you warm in extreme cold because of its lighter weight.
✔️ Temperature rating: You won't see this on all jackets when you shop, but performance outerwear brands sometimes include a rating to let you know how warm the coat will be. It could be as simple as warm, warmer and warmest; other times you may find a specific temperature range.
✔️ Lining: Most winter coats for everyday use have a smooth interior fabric. For extra warmth in extreme cold, you can find styles with a fleece lining or advanced technical features, like ones that reflect your body heat back to you.
✔️ Coverage: Avoid shorter jackets if you're looking for the best possible warmth. Coats that have coverage around your neck and longer lengths that go to your knees are ideal for blocking out cold air.