READ MORESales fell 1.2% from a month earlier, led by a 7.4% drop in fuel transactions, the Office for National Statistics said. Analysts had on average expected a far smaller 0.5% drop.
Food store sales fell 0.6% as supermarket sales dropped 1.3%. But sales rose 11.8% at specialist food retailers and 9.5% at off licences as shoppers opted for local stores during the bad weather.
Department stores were the only retail sub-sector where sales rose. The ONS said the 0.8% increase was probably linked to shoppers taking up online offers for Easter and Mother's Day when the weather was bad.
Online sales were 17.4% of all retailing in March, up from 15.9% a year earlier. Department store online sales rose by a third from a year earlier.
Ben Brettell, senior economist at Hargreaves Lansdown, said: "The weather meant a disappointing retail sales reading for March was all but guaranteed, but the figures were even worse than anticipated."
Businesses across the UK were hit by the "Beast from the East" - a Siberian weather system that brought heavy snow, wind and freezing temperatures in March. The bad weather added to problems faced by retailers as household budgets are squeezed by rising prices and consumers move online or spend their money on experiences rather than physical goods.
The sharp drop in overall sales for March caused a reduction for the whole of the first quarter. The quantity bought in the three months to March fell 0.5% from the final quarter of 2017.
Rhian Murphy, a statistician at the ONS, said: "Retail sales fell in the first quarter due to a large decline in March with petrol sales seeing a significant slump as a result of the poor weather keeping many shoppers indoors. However, the snow actually helped boost online spending with department stores in particular seeing growth in their web sales." ■