Sales at department store group John Lewis rose 18.9% to £51.3m last week as customers bought into summer lines.

Against the comparable period last Easter, the increase in the week to April 17 was 13%.

Fashion delivered the strongest rise of 27% as products such as sunglasses and sandals were snapped up and schoolwear had a “late surge”, said John Lewis head of multichannel Simon Russell. Home sales rose 25% as outdoor items such as beach chairs and picnicware did well.

Electrical and home technology sales were “in line with last year” Russell said, and it was a comparatively quiet week for vision products. The arrival in stores of 3D televisions raises hopes of “a return to form”, however.

John Lewis’s Oxford Street and Peter Jones stores in London were the strongest performers over the week, delivering 30% increases each.

Russell said: “Many branches might have seen even stronger results if it were not for the beautiful weather towards the end of the week that lured a lot of us to spend the day in the garden rather than visiting the high street.”

Sister grocery chain Waitrose recorded a 26.9% sales advance to £92.2m and also benefited from warm weather.

Sales of picnic food and prepared salads and fruit climbed 40% and ingredients such as mozzarella cheese were up by 43%.