Costco’s Sales Rise in June. It Was a Big Month for Summer Holidays.

A shopper loads items into a vehicle at a Costco store in Vallejo, California. (David Paul Morris/Bloomberg)

Summer holiday shopping reignited Costco Wholesale’s hot streak.

The retailer said Wednesday that its net sales rose 8% year over year in June to $26.4 billion, accelerating from May’s 6.8% gain. The increase snaps a string of five consecutive months of slowing sales growth.

Total-company same-store sales, which measure sales growth at stores that have been open for more than a year, grew by 5.8% from last year, compared with a 4.3% increase in May.

Stripping out fluctuations in gas prices and foreign exchange, same-store sales jumped 6.2%, also an improvement from May’s 6% rise.

For accounting purposes, the retail month of June actually ended July 4, which means June’s results encompassed three popular holidays—Father’s Day, Juneteenth, and Independence Day. Costco executives said better-performing product categories included candy, food, and cooler items, as well as meats and produce—all key components of a good, old-fashioned, summer barbecue.

Strong consumer demand from abroad also helped lift sales. Same-store sales excluding gas and foreign exchange jumped 7.9% in Canada and 8.2% in the dozen or so other countries Costco has warehouses in. U.S. same-store sales, meanwhile, rose 5.5% in June.

Costco’s e-commerce business also had a good month, with an 11.2% increase in same-store sales.

Shares of Costco were up 1.1% to $993.05 in the after-hour trading session Wednesday. The stock closed 0.4% lower.

Consumers have flocked to Costco in recent years, lured in by the retailer’s treasure-hunt model and bulk pricing.

Write to Sabrina Escobar at sabrina.escobar@barrons.com