Hello, and thank you for calling Costco Wholesale Corporation. I'm David Sherwood, AVP of Finance and Investor Relations, and I will review our sales results for the five-week retail month of September, which started on Monday, August 30th, and ended on Sunday, October 3rd. This period is compared to the five weeks that began last year on Monday, August 31st, and ended on Sunday, October 4th. This call will include forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements involve risks and uncertainties that may cause actual events, results, and/or performance to differ materially from those indicated by such statements. The risks and uncertainties include, but are not limited to, those outlined in today's call and sales release, as well as other risks identified from time to time in the company's public statements and reports filed with the SEC.
Forward-looking statements speak only as of the date they are made, and the company does not undertake to update them except as required by law. As reported in our release, net sales for September came in at $19.50 billion, an increase of 15.8% from $16.84 billion last year. Comparable sales were as follows. On a reported basis, five weeks, U.S. was at 14.6%, Canada, 14.9%, other international, 12.0%, total company, 14.3%, E-commerce, 10.6%. Comparable sales, excluding the impacts from changes in gasoline prices and foreign exchange, were as follows. For the five weeks, the U.S. was at 10.0%, Canada, 7.3%, other international, 8.0%, total company, 9.4%, and E-commerce, 9.6%. Our comp traffic or frequency for September was up 7.2% worldwide and up 7.4% in the U.S. Foreign currencies YoY relative to the U.S. dollar impacted total and comparable sales as follows.
Canada, positively by approximately 4.9%, other international, positively by approximately 2.8%. Total company, positively by approximately 1.1%. Gasoline price inflation positively impacted total reported comp sales by approximately 3.8%. The average selling price was 41% higher YoY at $3.38 per gallon this year compared to $2.40 last year. Worldwide, the average transaction for September was up 6.6%, which included the positive impacts from gasoline inflation and FX. In terms of regional and merchandising categories, the general highlights were as follows. U.S. regions with the strongest sales increases were Texas, Southeast, and San Diego. Other international and local currencies, we saw the strongest results in Mexico, U.K., and Japan. Moving to merchandise highlights, the following comparable sales results by category for the month exclude the positive impact of foreign exchange. Food and sundries were positive mid to high single digits. Sundries and candy were the strongest departments.
Fresh foods were up mid to high single digits. Better performing departments included service deli and bakery. Non-foods were positive low double digits. Better performing departments included home furnishings, jewelry, tires, and garden. Ancillary business sales were up low to mid 40s. Gas, Food Court, Optical, and Pharmacy were the top performers in the month. Looking ahead, the October reporting period will include the four weeks beginning October 4th and ending October 31st, compared to the four weeks beginning October 5th and ending November 1st, 2020. October sales will be announced Wednesday, November 3rd at 1:15 P.M. Pacific Time. If you have any questions regarding our September sales results or any other investor relations questions, please call Bob Nelson at 425-313-8255, Josh Dahmen at 425-313-8254, or myself, David Sherwood, at 425-313-8239. This recording will be available until 5:00 P.M. Pacific Time, Wednesday, October 13th. Thanks for calling.
Have a great day.