Costco
Customers walk by the membership counter at a Costco store on July 11, 2024 in Richmond, California. Justin Sullivan/Getty Images

Retail giant Costco reported a year-to-year 9% increase September net sales and comparable sales on Wednesday, with the East and Gulf coast port strikes and Hurricane Helene receiving credit for a late push to close the month.

Costco reported September net sales of $24.62 billion, up from $22.59 billion at this time last year. Total comparable sales for September rose 6.7%, however, that figure was 8.9% when adjusted for the impact of gas prices and foreign exchange.

In its monthly financial statement, Costco pointed to man-made events and acts of nature for a strong finish to September. The International Longshoremen's Association's strike, which lasted only three days, and the devastation of Hurricane Helene prompted a jump in retail sales as suppliers and builders stocked up.

"This year's total and comparable sales for the retail month of September benefitted by approximately two percent in the U.S. and one and one-half percent worldwide as a result of the increased sales in the final week of the month due to abnormal consumer activity associated with Hurricane Helene and port strikes," Costco said in a statement.

Costco (COST) saw its stock gain 2.1% ($909.10 per share) on Wednesday.