Dr Martens has warned its earnings will fall below expectations after the bootmaker's business was hit by warmer autumn weather and weak US sales. The famous brand, which first became popular in the 1960s, said its trade in the US had become more challenging in recent months and that two of its major wholesalers had reduced orders. Global profits for the firm fell by 55% to £25.8m in its half-year results. The profit warning saw shares plunge by almost 25% early on Thursday. Chief executive Kenny Wilson said trading in the second half of the year had been "mixed", with sales across the world impacted by warmer weather at the start of autumn. "In the USA, where there is an increasingly difficult consumer environment, our results have been more challenged, led by weakness in wholesale," he added. The company said in its results that widespread caution among Dr Martens wholesale customers had resulted in a "weaker order book than in prior years", but added that trade in recent weeks in Europe, the Middle East and Asia-Pacific had improved. Dr Martens makes more than half of its revenues from its most recognisable products, the eight-holed 1460 boot and sister product the 1461 shoe. But it has struggled with weakening demand in the US for some time, especially as the cost of living has increased around the world, with less cash for discretionary spending. In 2021, Dr Martens raised the prices of its footwear by £10 due to rising production and material costs, taking the price of its classic 1460 boots in the UK to £159 a pair. It has continued to rise and currently costs £169, according to the retailer's website.