Costco – Memorial Day 2021 by Rhonda June 2, 2021 590 5/31/21. Costco will be closed on Monday, May 31, 2021, in observance of Memorial Day. We are extremely grateful for those military men and women who have sacrificed their lives in service of our country. 0 FacebookTwitterPinterestEmail previous post Step 2 Double Showers Splash Water Table – Costco Sale! next post Whalen Industrial Metal and Wood Workbench – Costco Sale! 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