UK supermarket inflation slows as heatwave boosts picnic and ice cream sales

Shopping baskets took on a decidedly summery complexion during last month’s heatwaves as consumers filled up on a British picnic staple: picky bits, and grocery inflation slowed.

Spending rose on foods such as potato salad, olives and coleslaw, while ice-cream sales also increased, according to new data from Worldpanel by Numerator, a market research company.

But shoppers also turned to deals to save money, causing grocery price rises to slow to their lowest rate in nearly two years. Supermarket prices rose by 2.1% in the four weeks to 9 August, Worldpanel said on Tuesday, well below the 2.6% increase recorded in the previous month and the slowest increase since October 2024.

Nearly one-third of all sales across UK supermarkets were part of a promotion, as shoppers tried to keep costs down. The 31.3% of sales coming from deals was the highest level this year.

Spending also fell back after a bumper period during the men’s football World Cup in June and July. Shoppers spent £410 on groceries on average over the four weeks – £14.24 less than the last period.

As the scorching temperatures continued into August sales of dips were up by nearly a quarter compared with the same period last year, while coleslaw and potato salad increased by similar amounts. Quiches, olives and chilled “finger foods” also recorded sales increases.

And while the sustained heat caused some freezer aisles to falter, shoppers made an extra 6.2m trips to the cold section compared with the same period last year. Ice-cream and sorbet products posted a 26% increase in sales, while frozen fruit sales soared by 48%.

Sally Ball, the business unit director at Worldpanel by Numerator, said: “The continued heat across the UK has certainly impacted the way people are eating and drinking. Earlier this summer we saw that meal times were being pushed later in the day, with 13% of evening meals now eaten after 8pm.”

“Shoppers have been trying to stay cool this month, with soft drinks growing 15.1% in spend, while the freezer aisle saw shoppers stocking up on ice-cream, sorbet and frozen fruit to beat the heat.”

Separate research by NielsenIQ showed that people also spent more in convenience stores, which recorded their strongest sales growth in more than a year at 3.6% compared with equivalent period in 2025.

Online food shopping continued to outperform its in-store rivals, with e-commerce sales reaching £2.1bn, up 10% in value and 5% in individual item sales.

Part of that was down to food delivery platforms gaining market share, reflecting what researchers called “the growing demand for rapid access to refreshments”.

Mike Watkins, the head of retailer and business insight at NielsenIQ, said: “Growth has inevitably slowed after the peaks created by the Fifa World Cup, while the start of the summer holidays has given many shoppers a reason to delay some non-essential spending.

“As the weather becomes more seasonal towards the end of summer and children return to school, shopping baskets will start to reset, so there is the possibility of a short-term return of money off vouchers to help shoppers save money as well as to encourage more visits.”