Blizzard warnings stretched from New Jersey to Maine. Forecasters expected up to 20 inches of snow in Philadelphia and Boston and up to 16 inches in New York City.
"The forecast will tend to keep (shoppers) at home. It's not the best day for shopping," said Scott A. Bernhardt, chief operating officer at weather research firm Planalytics.
At least one mall, MacArthur Center in Norfolk, Va., planned to close early because of the snow.
The timing could have been worse for retailers. Last year, a snowstorm hit the East Coast the Saturday before Christmas, costing them about $2 billion lost sales.
"People will just wait a day to do exchanges and use their gift cards. It's no big deal," said Greg Maloney, CEO of the retail practice of Jones Lang LaSalle, which manages malls across the country.
Besides the East Coast, shoppers came out in force on Sunday. The nation's largest mall, the Mall of America in Bloomington, Minn., expected 100,000 shoppers. A respite from heavy snow that's battered the Twin Cities brought in the big crowd.
The mall expects its stores' holiday revenue to rise 8 percent over last year, mall spokesman Dan Jasper said.
So far, it's been the best holiday season for retailers since 2007, which was a record year. The week ending Jan. 1 makes up less than 10 percent of the Nov 1-Dec. 31 season but accounts for more than 15 percent of holiday spending, research firm ShopperTrak says. Analyst say holiday season spending is on track to rise 3 to 4 percent, the best percentage increase since 2006.
The snow will send some shoppers online, where sales have been strong compared with last year. Online spending rose more than 16 percent the week ending Christmas Day, IBM Coremetrics said. The average order rose 13 percent to $192.52.
From Nov. 1 through Dec. 19, total online spending rose 12 percent to $28 billion, according to research firm comScore Inc. At Atlantic Station in downtown Atlanta, shopping picked up in late morning as a rare snowfall began melting.
Shelly Melby, 43, said her family will likely spend $400 to $500 on post-Christmas deals.
"Just looking at the sales," she said. "The kids are looking for clothes."
Some shoppers couldn't find what they wanted. At Best Buy at Atlantic Center mall in New York, Marie Brown was disappointed that a laptop computer advertised at $200 was no longer available.
"We should have come earlier," she said. She bought a different laptop at $60 off. "We still saved money."
But others were pleasantly surprised. Joelle Lee, 33, and her cousin, Rebecca Jardine, 18, hit Pembroke Lakes Mall in Pembroke Pines, Fla., early. They were looking for half-price Christmas ornaments and New Year's Eve outfits. Jardine splurged on a watch at Guess marked down 40 percent.
AP Writers Emily Fredrix and Sara Kugler Frazier in New York; Michelle Chapman in Livingston, N.J.; Ray Henry in Atlanta; and Barbara Rodriguez in Miami contributed to this report.