SavingAdvice.com Blog Fourth of July is a day filled with fireworks, family, and fun. But it’s also a federal holiday, which means your favorite stores could be closed. If you’re trying to figure out where to get your party supplies this year, you may be wondering, is Costco closed on 4th of July 2021? We’ll fill you in on your favorite warehouse store’s holiday hours below so you can decide where to shop on Independence Day. Is Costco Closed on 4th of July 2021? Unfortunately Costco will be closed on 4th of July 2021. Costco usually shuts its doors on federal holidays, and Independence Day is no exception. So if you need some bulk hot dogs or brownie platters for your backyard barbecue, you’ll need to plan ahead and go shopping early.