John Lewis sales rose 9.9% to £62.6m last week as it clocked up the best performance of the half.

The department store group said it benefited from “some pent-up demand following the recent warm weather and also the benefit of investment in new space”.

John Lewis buying director, home, Paula Nickolds said: “It seems many customers are starting to feel festive as sales of Christmas Shop and gifting ranges across our offer are already selling well.”

John Lewis opened three shops in the last four weeks. It also last week refurbished its Cheadle store.

Like-for-like shops showed a “significantly improved position last week”, as sales at Newcastle, Trafford and High Wycombe thrived in the week to October 15.

Nickolds said the retailer achieved a “stellar” result online, as sales surged 36%, driven by a “notable” uplift in web traffic.

Of its three categories, electrical home and technology delivered the strongest performance, up 10% on the same week last year, as sales of iPads grew.

Home sales grew 7%, as big ticket items sold well in a tough market. Upholstery surged 17% dining was up 13%.

Fashion grew 5%, with childrenswear up 11%. Nickolds said the “impact of the unseasonably warm weather was evident in outerwear and fashion accessories where trade was softer”. However, it added that this “looks set to change as more wintry weather arrives”.

Nickolds said: “We now find ourselves on the cusp of the Christmas sales build. Our combined focus will ensure we provide the most enjoyable shopping experience for our customers every time they visit us and capture every sale possible.”

At John Lewis Partnership’s grocery business Waitrose, sales grew 11.7% to £103.6m after the mixed weather “prompted an unusual mix of sales”.

Rupert Thomas, Waitrose marketing director, said that whole many cold-weather foods sold well, such as lamb joints and Italian ready meals, the bright sunshine also resulted in a rise in warm-weather foods such as prepared salads.

Seasonal products sold well, with sales of mince pies up 80% “as customers started to get in to the festive spirit”.

Waitrose is also selling 10,000 giant ‘Cinderella’ pumpkins for the Halloween period.

The essential Waitrose range saw sales up 13%.