You love Costco. I love Costco. Over 145 million cardholding members love Costco. But there is one day of the week that can turn your perfectly normal bulk shopping trip into something that feels like a contact sport. And if you keep showing up on that day, you have nobody to blame but yourself.
The day you should never, ever shop at Costco is Sunday.
I know, I know. Sunday feels like the obvious day to knock out the big grocery run. You slept in, had some coffee, maybe scrolled your phone for an hour, and then figured you’d swing by the warehouse to grab a few things. The problem is that literally millions of other people had the exact same idea at the exact same time. And Costco on a Sunday is a different beast entirely.
Sunday Is Costco’s Single Busiest Day
This isn’t just a guess or a feeling. One self-identified Costco employee on Reddit put it bluntly: “I work at Costco and Sunday is our busiest day of the week. Friday and Saturday tie for second.” That tracks with what pretty much every shopping expert and insider has confirmed. Sunday is the peak of the peak.
Part of the reason is simple math. Most people don’t work on Sundays, so the entire customer base funnels into one day. But it gets worse. Costco closes at 6:00 p.m. on Sundays, compared to 8:30 p.m. on weekdays. That means you’re cramming the same number of shoppers (actually more shoppers) into a much smaller window of time. The crowds get compressed into fewer hours, and you can feel it the second you pull into the parking lot.
The Parking Lot Alone Should Be a Warning Sign
A radio host in Michigan recently described a Sunday trip to the Cascade Costco on 28th Street SE that perfectly captures the experience. The parking lot was so full there was barely a spot to be found. What was supposed to be a quick run for a few items turned into an ordeal. The checkout lines were so long the host joked they might still be standing in line the next day. That’s not a unique story. That’s just what Sunday at Costco looks like across the country.
One Redditor described Sunday Costco shopping as “sensory hell,” and that post collected more than 130 comments from people agreeing. Another person recounted a Saturday trip and said, “Total nightmare, never again.” These aren’t isolated complaints. They’re a shared national experience.
Sunday Also Has the Fewest Food Demos
Here’s something that makes Sunday even more frustrating. A former employee on Reddit pointed out that Sundays actually have the fewest food demos on the floor. So you’re dealing with the biggest crowds and the longest lines, but you’re not even getting the full sample station experience that makes a Costco trip fun in the first place. You’re suffering for nothing.
Saturday Isn’t Much Better
If Sunday is the worst, Saturday is a very close second. A 2024 survey by Drive Research found that Saturday has actually overtaken Sunday as the busiest day for grocery shopping overall, especially between 10 a.m. and 2 p.m. At Costco specifically, Saturday afternoons are brutal. The combination of everyone being off work and having had time to eat breakfast before heading out creates a tidal wave of carts around midday. Weekend trips can leave you feeling like you need the rest of Saturday to recover from dodging carts, waiting in checkout lines, and standing in the exit line to have your receipt checked.
The Days After Holidays Are a Trap
Most people already know to avoid the day before a major holiday. The scramble for last-minute items the day before Thanksgiving or Christmas is the stuff of legend, with lines stretching all the way to the bakery section. But here’s what catches people off guard: the day AFTER a Costco closure is just as bad. Maybe worse.
Costco closes for New Year’s Day, Easter, Memorial Day, Independence Day, Labor Day, Thanksgiving, and Christmas. The day after each of those holidays, everyone floods back in to restock at the same time. Black Friday and July 5th are cited as some of the single worst days of the entire year. Redditors have described post-holiday Costco trips as straight-up “Madness” with a capital M.
Weekday Evenings Are Also Rough
Even if you’re smart enough to avoid weekends, you can still walk into a mess if you time it wrong. Weekday evenings from about 4 p.m. to 7 p.m. are packed with post-work shoppers. Kristen Markel, founder of Warehouse Wanderer (a site completely devoted to Costco shopping strategy), says these hours are filled with people who remembered they need toilet paper on the way home or are looking for something to heat up for dinner. The aisles get clogged and checkout lines get long.
Mondays and Fridays can be busy all day, too. Mondays are often restocking days at many Costco locations, meaning popular Kirkland products may not even be on the shelves yet. So you’re fighting crowds AND the shelves are picked over. Fridays have that end-of-the-week energy where families are loading up for the weekend.
Crowded Stores Actually Cost You Money
This is the part nobody talks about. A packed store doesn’t just waste your time. It messes with your spending. CouponCabin’s Chief Savings Expert Melanie Lowe points out that when aisles are jammed and checkout lines feel rushed, shoppers are more likely to grab random impulse items. You’re less likely to compare unit prices, read tags, or inspect seasonal items carefully. Shopping in a calm, uncrowded store literally protects your wallet.
And you miss the little stuff that saves real money. Prices ending in .97 often signal a markdown. Prices ending in .00 or .88 can mean local clearance. That asterisk on a price tag (sometimes called the “Death Star” by Costco insiders) means the item is being discontinued and won’t be restocked. You’re not catching any of that when you’re shoulder to shoulder with 500 other people trying to get out alive.
So When Should You Actually Go?
Every single source, every employee, and every shopping expert agrees on this: Tuesday, Wednesday, and Thursday are the days to shop at Costco. The sweet spot is mid-morning to early afternoon, roughly 10 a.m. to 2 p.m. By then, the staff has had time to restock shelves, the crowds are light, and most sample stations are up and running.
One Costco employee summed it up nicely: “Wednesday is when coupons start, so they can be super busy in the early hours of opening. With all that being said, I can safely say Tuesday nights is our least busiest.” Another Reddit user backed that up: “We went on a Tuesday at like 3:30 p.m. recently and it was the most pleasant Costco experience I’ve had in a minute.”
Laura Lamb, CEO of Costco Hot Finds, says Monday through Thursday between 1 and 3 p.m. is the quietest regular window. And if you’re really looking for a ghost town, the last hour before closing on a weekday (typically 7:30 to 8:30 p.m.) is about as empty as a Costco ever gets.
The NFL Loophole
Here’s a fun trick for football season. Sunday afternoons during NFL games (September through late January) can actually be surprisingly quiet at Costco. A huge chunk of the American population is parked on the couch watching their team, which means the aisles thin out. The Super Bowl window is apparently one of the best times all year to shop, according to multiple Reddit users. If you absolutely must go on a Sunday, at least time it with kickoff.
Executive Members Have a Secret Weapon
If you’re an Executive Member ($130 per year), you get early access to the warehouse. That means you can walk in at 9:00 a.m. Sunday through Friday, and 9:00 a.m. on Saturdays, a full half hour to an hour before regular members are allowed in. Those early morning slots are quiet and calm. Shelves are freshly stocked. There’s no competition for parking spots. It’s a completely different experience.
Use Google Maps Before You Leave the House
One last tip that multiple insiders and employees recommend: pull up your local Costco on Google Maps before you head out. Search for your store and look at the “Popular Times” bar graph. It shows you, hour by hour and day by day, how busy that specific location typically is. Click through the days and find the times labeled “Usually not too busy.” Every Costco is a little different, and this tool gives you real data for your exact store.
Shopping on a rainy day is also a surprisingly effective crowd avoidance tactic. People just don’t want to deal with loading bulk items into their car in the rain. Their loss is your gain.
The $1.50 hot dog combo will be waiting for you no matter when you show up. But if you want to actually enjoy the experience of getting to it, skip Sunday. Go on a Tuesday. Your future self will thank you.
