High street shops saw a like-for-like sales fall of 2.2% in April due to the bad weather, making it the fastest fall in a year.
Latest figures for May saw consumers take advantage of clearance sales to pick up bargain knitwear, with perfumes and cosmetics sales boosted by promotions and discounts.
The recent sunny weather has boosted sales of barbecue meats, salads and ice creams and swimwear.
David McCorquodale, head of retail at KPMG, which compiled the data, said: "While sales didn't soar through the roof, this is still a very creditable performance from UK retailers. Promoting the right product at the right price made the difference in May."
More top news
Greater Manchester Police's chief constable revealed the offences that drew attention to the future Manchester suicide bomber as a teenager.
Thousands of Beko tumble dryers could pose a fire risk through an overheating fault, the manufacturer has warned.
Labour leader Jeremy Corbyn was unable to provide the cost of his party's key manifesto plans on free child care.