Bad weather and the lure of online shopping saw consumers shun UK High Streets on one of the busiest days before Christmas.
Retail experts Springboard estimate numbers were 9% lower on Saturday, compared with the same time last year.
Including shopping centres and retail parks, footfall was 7.3% lower.
Retailers face a number of pressures including rising business rates, the national minimum wage and the impact of Brexit uncertainty on the pound.
On Friday and Saturday, Storm Deirdre brought freezing temperatures, gales, snow and rain to many parts of the UK, dampening any hope for a pre-Christmas retail bounce.
"If people are presented with really terrible weather, they then have the choice to shop online, and they can make other choices about what to do with their time," said Diane Wehrle, Springboard marketing and insights director.
"That unfortunately offers them sometimes better alternatives than trailing around a town centre or a High Street in freezing cold or rainy weather."
Trade was better on Sunday, with footfall up 0.1% compared to the same day last year.
However, Ms Wehrle said this was mainly people who had deferred shopping from Saturday because of Storm Deirdre.
Over Saturday and Sunday, Springboard said total footfall dropped by 4.3% against the same weekend in 2017, with the sharpest fall recorded on the High Street and in shopping centres.
Ms Wehrle said footfall appeared to have picked up for the early part of last week - with a year-on-year increase of 6.1% in High Streets, shopping centres and retail parks.
But she pointed out that snow last year meant that the comparative figures were already low.
Ms Wehrle said Saturday's figures were "severely down" on last year, on what she described as a "peak trading weekend".
Next weekend may be too close to Christmas Day for shoppers to venture out, she added, predicting a difficult week ahead.
Ms Wehrle said the trend now to discount items before Christmas and having all-year-round sales was affecting consumer's attitude towards price cuts.
"We have come to expect discounts," she said. "By the time we get to Christmas we've seen 20% off, we've seen 30% off, we've had Black Friday."
Despite the gloomy outlook, Rachel Lund, head of insights and analytics at the British Retail Consortium, believes shoppers may still make last-minute purchases in the days running up to 25 December.
"While we have seen a slow start to the Christmas period, changing technology and shopping habits means that many consumers will be leaving their shopping to the last week before Christmas - historically the most important for retailers," she said.
"Nonetheless, given the challenging year on the High Street, retailers will be hoping for strong sales this weekend and next as consumers buy both food and presents before Christmas Day."