The gloomy nature of a rain-soaked June resulted in weaker retail sales in the UK, according to the British Retail Consortium (BRC) and KPMG.
Like-for-like sales slumped 0.5% as the weather significantly impacted on the number of people buying their t-shirts, shorts, flip flops and sunglasses for a Great British summer.
With much of the data collected by the EU referendum, Helen Dickinson, chief executive of the BRC, said it was too early to judge the impact of the Brexit vote on retail sales.
David McCorquodale, head of retail at KPMG, said: "While the ramifications from the Brexit vote may well affect consumer confidence, retailers will be hoping the long-promised heatwave and potential stay-at-home holidays will be enough to drive shoppers back to the high-streets."
The figures do show, however, that total sales did start to slow down towards the end of the month, after the referendum result.
Much hinges on consumers' confidence to head to the shops and make purchases. Around 75% of the UK's economy depends on the service sector. But a separate study published last week found that consumer confidence suffered its sharpest fall in 21 years following the Brexit vote.
The survey from market researcher GfK found that 60% of consumers expect the UK economy to worsen over the next 12 months, up from 46% earlier in June.