And web sales are up 11% from August, IMRG and Capgemini report.

The months may be getting cooler in Britain but web sales are heating up, according to the latest online retail spending report from IMRG, an e-retail trade association in the United Kingdom, and consulting firm Capgemini.

U.K. consumers spent 6.4 billion pounds (US $10.25 billion) online during September, up 16% from a year earlier and up 11% compared with August, and online-only retailers’ web sales grew 3% faster than those of than multichannel retailers, the report says. For the fourth quarter, IMRG and Capgemini forecast that online spending will rise 15% year over year.

Mobile web sales proved a bright spot last month, rising 312% compared with last year. Additionally, the conversion rate for mobile rose to 1.9%, the highest thus far in the United Kingdom, the report says.

“The upward trend in mobile conversion rate indicates the steady infiltration of smartphones and tablets as a buying device, which used to be more of a browsing tool,” says Chris Webster, head of retail consulting and technology at Capgemini. “Online retailers should wake up to this change and include a smartphone mobile shopping application or mobile web in their multichannel offering platter.”

Looking at categories, gifts tallied up strong web sales growth of 54% year over year, hinting that U.K. consumers are taking advantage of summer overstock discounting and starting holiday shopping earlier. Online clothing sales, meanwhile, grew 18%, the highest year-over-year growth since October 2011, benefiting from the early and unexpected cool weather in the second half of the month, the association notes.


“The Queen’s Jubilee, the European Championships, the Olympics and a capricious weather pattern have all left their indelible marks on this year’s e-retail trajectory,” Webster says. “September marked the return of online retail to strong double digit growth levels and rounded off Q3 on an encouraging note.”

The Queen’s Jubilee was the celebration of Queen Elizabeth II’s 60th anniversary on the throne. The European Championships is a popular European soccer tournament.

The IMRG Capgemini Index follows online sales of around 100 U.K. retailers, including, No. 39 in the Internet Retailer Europe 400 and, No. 3.