Waitrose sales for the week ending Saturday April 23 were £114.7m, up 10.6% on Easter last year.
The grocer reported its biggest sales ever on an Easter Saturday with sales up 15% on the previous year.
Managing director Mark Price said: “The celebratory mood has helped drive a very strong week’s sales, with products we’d normally associate with high summer performing exceptionally well. Customers are enjoying the holiday and the fine weather whatever their budget, with a wave of alfresco entertaining over the Easter Weekend from picnics and barbecues to the traditional Sunday Roast.
“Shoppers are already stocking up for their royal wedding celebrations – whether it’s a fully fledged street party or simply a glass of English fizz with family and friends.”
Sales of barbecue foods were up 25% as Waitrose launched its barbecue meat range a month earlier due to the surprise heatwave.
Customers are already stocking up on party fare for the Royal Wedding on Friday, the grocer said, with traditional buffet foods such as sausage rolls performing well. Waitrose expects to sell more than a million cocktail sausages for the Royal Wedding weekend.
Waitrose has already sold enough bunting to decorate the route from Westminster Abbey to Buckingham Palace more than 15 times.