Many U.S. consumers stayed away from malls and headed online to take care of their holiday shopping last weekend as a major snowstorm hit the East Coast, data released on Tuesday showed.

Retail sales on Saturday fell 12.6 percent, while traffic in U.S. stores fell 12.4 percent, according to ShopperTrak.

But online shopping jumped 13 percent from the same period a year ago to $767 million during the final weekend before Christmas, when snow blanketed much of the Northeast.

The Saturday before Christmas, which fell on December 19 this year, is known as Super Saturday since it is often one of the biggest shopping days as shoppers head out to buy gifts.

This year, Washington, D.C. and other parts of the East Coast were hit with several inches of snow, putting a damper on expected spending.

Mother Nature was very unkind to retailers on Saturday as the year-over-year sales decline was the largest we've seen since we began reporting this number in 2002, ShopperTrak co-founder Bill Martin said in a statement.

The Northeast posted the steepest sales decline of any region of the United States, with a 17.3 percent drop, ShopperTrak said.

Sales in the full week ended December 19 fell 1.2 percent from a year earlier, while sales from Friday, December 18 through Sunday, December 20 fell 2.1 percent to $18.8 billion, ShopperTrak said.

Online sales rose 6 percent to $4.8 billion last week, setting a one-week sales record. Tuesday, December 15, was the heaviest online spending day ever, with $913 million in transactions.

Retailers have been very aggressive with late season promotions, while informing consumers that they could still get their purchases shipped in time for Christmas, and these tactics seem to be paying off, comScore Chairman Gian Fulgoni said in a statement.

For the first 50 days of the November-December holiday season, online spending reached $25.52 billion, up 4 percent from the corresponding days last year, comScore said.

(Reporting by Jessica Wohl; editing by Matthew Lewis and Andre Grenon)

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