Costco – Memorial Day 2021 by Rhonda June 2, 2021 797 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 Costco Coupon Book APRIL 2025 Costco Business Center Coupon Book: APRIL / MAY... Costco Hot Buys Sale: 3/29/25 – 4/6/25 Permasteel 46″ Rolling Work Bench at Costco! Bond Bloomington Cascading Cup Fountain at Costco! Costco Unadvertised Sales! MARCH 2025