The International Council of Shopping Centers-Goldman Sachs weekly retail tracking report said sales dropped 5.4 percent from the previous week and 1.7 percent compared to the same week of 2013.
After a strong finish to the holiday gift-buying season, customers pulled back, ICSC said in a Tuesday news release.
"The final week of the fiscal month was soft ... accentuated by adverse weather conditions in the Midwest and East, which hindered shopping over the past week," said Michael Niemira, ICSC vice president of research and chief economist.
Niemira said December sales would likely show an increase of 4 percent to 4.5 percent.
"This is somewhat above our earlier expectation as Walgreen's already reported a very strong December performance," he said.