Department store giant John Lewis today blamed soaring temperatures for a slowdown as knitwear sales wilted in the sunshine.
The retailer said like-for-like sales growth through its 33 stores and website dropped to 0.1% in the week to September 24, against a 15.1% increase a year ago.
Nat Wakely, director of selling operations, said fashion unusually failed to beat its performance last year - with a 0.7% decline compared with a 3% increase - but this was down to the effects of the weather.
Temperatures have soared to 28C - more than 10C higher than September averages - encouraging people to go the park, get out the barbecue and visit friends rather than go shopping.
Mr Wakely added: "The knitwear figures tell it all in terms of the weather when compared year-on-year."
John Lewis said home sales fell by 1.7% over the past week as big ticket items slowed, though linens did well, while seasonal gifts jumped by 18%.
Electrical and technology rose by 4.1%, while online growth slowed to 21%, its smallest rise in September.
John Lewis Partnership's supermarket arm Waitrose enjoyed an unexpected boost from the hot spell as ice cream sales jumped by 15.8% while soft drinks and cider jumped 20% and 50% respectively. Total sales over the week rose by 8.8%, compared to 19.5% a year ago.
Retail director Tony Solomons said the group had also started selling its hugely popular Heston from Waitrose Orange Christmas Pudding created by top chef Heston Blumenthal.
Mr Solomons said: "The £13.99 puds, which contain a whole candied orange, are flying off the shelves and are already appearing on the auction site eBay."
He added that Waitrose had ordered three times as many for this Christmas after selling out last year and will also introduce a Heston from Waitrose-branded Hidden Clementine Pudding, a smaller version for two people.