Severe cold weather hit UK shoppers on the last weekend before Christmas.
On the so-called "super Saturday" millions braved snow and freezing temperatures to buy gifts.
The impact of the January rise in VAT and disruption to online deliveries was expected to contribute to good sales.
But one of the UK's largest shopping centres, Brent Cross in London, closed its doors early on safety grounds as wintry showers hit the capital.
"Due to adverse weather the centre is now closed. At the moment we hope to open the centre tomorrow," the centre, in north London, said on its website.
Jace Tyrrell, from the New West End Company which represents retailers in London's Bond Street, Oxford Street and Regent Street, said: "Although footfall was slightly down on forecasts the shoppers that braved the icy conditions were spending.
"Many retailers have reported sales up on last year with jewellery selling fast and technology strong, in particular the 'must have' items for this Christmas, 3D TVs and the Apple iPads."
Improved weather on Sunday was boosting retailers hopes of continuing sales.
"With many online deliveries not guaranteed now for Christmas, shoppers have no real choice but to visit the high street and complete their Christmas shopping lists," Mr Tyrrell said.
In Manchester's Trafford Centre, more than 20 tons of grit was used across the 150-acre site over 24 hours to make the roads and car parks accessible.
Retailers were reporting "buoyant" trade, director of operations Gordon McKinnon said.
"While the malls were naturally quieter at the start of the day, shoppers here are definitely on a mission to spend and by lunchtime everything was in full swing.
"Our stores are telling us today that electricals and homewares are doing particularly well, with many shoppers bagging the big-ticket items now before the VAT hike in early January affects pricing."
In Scotland, retailers in two shopping centres reported an increase in the number of shoppers compared with last year.
Scotland's biggest shopping centre, Glasgow Silverburn, reported a 20% increase in footfall on last year.
With many online retailers cancelling deliveries to Scotland after earlier heavy snowfalls, customers appeared to have opted to go out to shop.
A Silverburn spokeswoman said: "It's been a pretty significant rise this year. We were down around 7% on the previous year when the snow was at its worst so we're happy that people are coming back.
"I think there's been a bit of a backlash against the online retailers because of the delivery problems."
Union Square in Aberdeen reported an increase of up to 30% compared to last year.
Union Square shopping centre general manager Ryan Manson said: "Last Saturday was our busiest of the year to date and so far, the figures are looking good to smash that target today.
"Despite another day of wintry weather, we're seeing queues out the door in some of our stores. We've drafted in extra staff to help us with another bumper weekend."