Britain's supermarkets have failed to beat last year's bumper summer, with sales almost flat in the past three months.
In the 12 weeks to August 11, year-on-year supermarket sales stalled, data from Kantar revealed.
All of the "Big Four" supermarkets - Asda, Morrisons, Sainsbury's and Tesco - saw a dip in sales and smaller market share during the period.
Sainsbury's showed the smallest dip in the cohort of 0.6%, driven by higher levels of promotion which helped boost sales of branded goods.
However, Aldi posted a 6.2% increase in sales, supported by an 11% rise in bakery products and a 13% increase in biscuits.
The figures show nearly half of all households in the UK have shopped in an Aldi store in the past three months.
Meanwhile, Ocado was the fastest-growing UK grocer, notching up a 12.6% rise.
But the online supermarket only accounts for 1.4% of the market.
Lidl's growth was the next fastest, at 7.7%, to give the discounter a record total market share of 5.9%.
Fraser McKevitt, head of retail and consumer insight at Kantar, said: "The memory of last year still looms large for retailers and this summer's comparatively poor weather, combined with low levels of like-for-like price rises, have made growth hard to find for retailers.
"July's hottest day on record wasn't enough to shift the market into growth, but the grocers will have been encouraged by glimpses of better weather during the past four weeks which helped boost sales of summer staples like hayfever remedies, suncare and burgers by 17%, 8% and 5% respectively."
