Online sales surged 17% year-on-year in July as the warmer weather and Olympic fever triggered online shopping, according to the IMRG Capgemini e-Retail Sales Index.

£6.5bn was spent online during the month, up 9% on June’s figures, the highest growth in online sales this year.

Online only and catalogue retailers recorded year-on-year growth of 19.5% in July, trading above multichannel retailers -  which posted 15% growth – for the seventh consecutive month. The same growth trend was seen across basket spend where pureplay retailers recorded an average spend of £101, up 23% on the last year.

Average basket orders at multichannel retailers fell 1% at £198 against £200 last year.

Clothing, electricals and travel all drove online sales in July.

Capgemini head of retail consulting and technology Chris Webster said: “While we won’t know the direct impact the Olympics has had on the sector until next month, the excitement and build up to the Games certainly contributed to July’s strong performance.”

Clothing sales returned to double digit growth in July, advancing 15% year-on-year and 18% on June boosted by sunny spells and retailers continuing to cut prices.

The introduction of autumn lines also helped increase sales as shoppers were encouraged to update their wardrobes earlier than usual.

Electrical sales soared 30% due to wet weather in the month, as well as shoppers buying high definition televisions to enjoy the Olympics on.

M-commerce sales continued to rocket in the month, posting a 313% increase in the month, although this growth was not at the same level as previous months in May and June, which advanced 350% and 356% respectively.