Upmarket supermarket chain Waitrose has reported its total sales rose 4.6% to £123.49 million in the week to June 7.
The warm weekend meant many people opted for outdoor dining.
Sales of meat rose by 20% on Sunday – the grocery chain said it sold 29% more sausages and 91% more of its speciality barbecue meat ranges.
In other food categories, the warm weather led to sales of salads and sushi increasing by 15%.
The supermarket sold 52% more ice cream on the Sunday than at the same time last year.
Meanwhile, sales at sister company John Lewis soared 18.2% to £70.8 million for the same week.
The weather worked in its favour, said Simon Russell, director for retail operations development at John Lewis.
Occasional rain drove "footfall into branches” while the sun stimulated strong seasonal performances.