Growth was driven by a strong performance from household goods stores, data from the Office for National Statistics (ONS) shows.
The proportion spend online soared to the highest on record – 33.4% in May, compared with 30.8% in April.
However, in the three months to May the volume of retail sales decreased by a record 12.8%.
Jonathan Athow, ONS deputy national statistician for economic statistics, said: “Retail sales partially rebounded from the significant falls seen over the last two months, although total sales were still well over 10% down on February.
”It was another record month for website orders with a third of sales now online, as many retailers expanded their internet presence.”
Non-essential retail stores in England were allowed to reopen with social distancing and other safety measures in place on 15 June.
Meanwhile, it was announced yesterday that high street shops will be allowed to reopen in Scotland from 29 June.
Industry observers emphasised the importance of finding improving the customer experience, both in stores and online, to build on the momentum.
Commenting on the ONS figures, Silvia Rindone, partner in consumer product and retail at accountancy firm EY, said: “Peak lockdown saw sales fall as consumers prioritised essentials and cut back everywhere else. Images of long queues outside re-opening shops this week clearly show pent-up demand, especially among younger consumers. There are green shoots for the retail industry that things may improve.
“This is a good short-term result, but thinking longer term we expect this initial spike to fall back as consumers remain cautious and the economic impact of Covid-19 continues.
“In this new era, retailers must do all they can to help alleviate customers’ concerns if they are to prosper beyond Covid-19. People need to know the shopping environment and communal space is safe and that the brand is taking health and safety as seriously as they are.
“This is also a time for retailers to really reflect on their digital capabilities to help improve the customer experience – in-store and online.”
Lee Lucas, principal and CEO of the Fashion Retail Academy, added: “It has been a long and challenging few months for high street retailers, but it’s encouraging to see that today’s figures show a healthy rebound from last month’s record drop in retail sales.
“The queues we saw on high streets this week shows that many shoppers have missed the in-store experience, and were keen to enjoy some retail therapy after months stuck at home.
“With shoppers demonstrating they are willing to return to physical stores, retailers need to make the most out of this situation and ensure this momentum continues.
“Proactive engagement with customers via digital channels about in-store offers and discounts, along with demonstrations of how they are enabling social distancing and keeping staff and shoppers safe, will be critical to encouraging return visits.”