Retail sales rose 1.4% in June compared to the same month last year, according to figures released by the British Retail Consortium (BRC).
It had been predicted that like-for-like sales would drop 0.4% in June, so the increase has led to hopes that consumers are beginning to spend again.
"June's sunshine gave overall sales a much-needed boost. The heatwave helped food retailers and got customers buying outdoor goods, such as garden furniture, pools and picnicware," said Stephen Robertson of the BRC.