Costco Closed on Labor Day 2019 by Rhonda February 15, 2021 263 9/2/19. Costco will be closed on Monday, September 2, 2019, in observance of Labor Day. 0 FacebookTwitterPinterestEmail previous post Costco – Synergy Kammi Pushback Recliner next post Costco Sale – Klamath Fireplace Mantle You may also like Costco Unadvertised Sales! JUNE 2023 Solo Stove Mesa Tabletop Fire Pit 3-Pack at... Costco – Memorial Day 2023 Happy Hop Shark Cave Adventure Inflatable Water Slide... Lemon Meringue Cheesecake from Costco’s Bakery! Squishmallows Macaron Lip Balms at Costco!