The UK retail sales values, on a like-for-like basis, increased 1.3% in March 2012 from the same month a year ago, when sales fell 3.5%, according to the data released by British Retail Consortium (BRC).
On a total basis, retail sales were up 3.6% in the month, against a 1.9% decrease recorded in March 2011.
Food sales growth was unchanged from February, but non-food sales growth improved in March.
The agency said unusually warm sunny weather in the month helped clothing, footwear and outdoor leisure.
Sales of indoor homewares remained down on a year ago, with larger purchases in particular hit by consumer caution.
Online sales of non-food items showed stronger growth, but against a very weak March 2011, rising 13.9% on a year ago, the best since December 2011.
BRC director general Stephen Robertson said the unusually warm weather in March brought some welcome sunshine into the lives of non-food retailers.
"The early signs of summer got people buying clothes and shoes for the new season. Gardening items and outdoor leisure also saw a lift," Robertson said.
"It's worth remembering the sales comparison is against the weakest month of last year, largely caused by the movement of Easter in the calendar, and we'll have to see whether this is additional spending or just shopping which has happened earlier than usual.
"Food sales growth continues to be largely underpinned by food inflation rather than by customers buying more.
"The overall retail environment is still difficult. Discounting remains a key tactic for retailers trying to encourage consumers to spend, particularly on big indoor items.
"People are still struggling to balance household budgets against expensive fuel and utilities. The warmth of March was a help but it will take more than a week of sunshine to transform retailers' fortunes."
KPMG Retail head Helen Dickinson said the clothing sector as a whole and non-food generally benefited from the warm March weather.
"Increases in food prices rather than volumes was one of the factors behind the uplift in this month's figures," Dickinson said.
Image: Online sales of non-food items showed stronger growth, but against a very weak March 2011, rising 13.9% on a year ago, the best since December 2011. Photo: watcharakun