Costco Closed on Labor Day 2021 by Rhonda September 6, 2021 454 9/6/21. Costco will be closed on Monday, September 6, 2021, in observance of Labor Day. 0 FacebookTwitterPinterestEmail previous post Kirkland Signature Nativity Set at Costco! next post Costco.com Labor Day Sale! 2021 You may also like NEW Orange Dreamsicle Cheesecake at Costco!! Costco Coupon Book AUGUST 2024 Costco In-Warehouse Hot Buys Sale – JULY 2024! Costco Business Center Coupon Book JULY / AUGUST... Costco Sale: Kirkland Signature Hexagon Dog Bed Costco Member Savings Days 7/15/24 – 7/19/24