Shoppers spent £5 billion online in July, the most in any month this year, according to latest issue of the IMRG Capgemini e-Retail Sales Index.
Brits typically spent £81 per person online, with millions of pounds splashed out on summer holidays booked through the web.
Online spending was 18 per cent higher in July than during the same month last year, the largest increase seen since before the recession.
Shoppers were attracted to websites by retail promotions as well as the wet weather, which led to a degree of online 'retail therapy'.
David Smith, managing director of IMRG, said that online sales growth comes as little surprise given the fact that half of the UK population uses the internet on a daily basis.
"The evidence mounts that high street retailers will need to invest more in their online business and put it at the heart of their retail strategy," he said.
"Online retailers, on the other hand, will need to continue to innovate as they strive to close the growth gap."
