The July heatwave contributed to sales growth rates almost twice that achieved by the UK’s leading supermarkets during the London 2012 Games – one of last year’s peak sales periods – according to the latest retailer performance figures released by Nielsen.

Aggregate sales value growth for the UK’s leading supermarkets during the four weeks ending 20 July 2013 was up 6.4% year-on-year – a rate comfortably ahead of any ‘non-event’ four-week period in the last two years. For the previous four-week period (ending 22 June 2013), year-on-year sales value growth was up 2.3%.

Unit sales (volume) increased 3.0% year-on-year, compared to +0.1% year-on-year during the previous four weeks.

Explaining the figures, Nielsen’s UK head of retailer and business insight Mike Watkins said: “The supermarkets basked in the heat and in growth levels not seen for some time, as shoppers stocked up on fresh foods and refreshments. The increased visits and incremental spend was enough to compensate for the weaker performance of ambient grocery and household.”

The strongest category growths were in soft drinks (+27% value year-on-year), beers, wines & spirits (+16%, driven by cider and lager) and frozen (+14%), helped in particular by ice-cream and desserts.

Watkins commented: “At the height of the heat wave, the week ending 13 July, an extra seven Olympic swimming pools worth of bottled water were sold compared to the first two weeks of July 2012 – worth an extra £15m. Consequently, bottled water overtook Cola as the largest soft drink sector by volume.”