Halfords shares hit a four-year high this morning as warm weather helped to boost the retailer’s profit outlook for the year.

The bicycle and car parts chain said the ‘heightened seasonal demand’ for its products, including air conditioning, had delivered an extra £5million in profits.

An unusually warm summer has driven demand, with annual results now expected to be weighted to the first half, it said.

It now expects annual pre-tax profits of between £55million and £65million, above previous expectations of £52.6million.

Shares surged 11 per cent at the open to 271p, bringing year-to-date gains to over 90 per cent.