The International Council of Shopping Centers-Goldman Sachs weekly sales report said sales rose 1.4 percent over the previous week and 2.3 percent over the same week of 2012.
Sales were stronger at grocery and clothing stores, discount stores and wholesale clubs, the weekly report released Tuesday said.
Weather Trends International said temperatures averaged 0.2 degrees Fahrenheit colder than the same week a year earlier. However, the week's temperatures were slightly warmer than the week's long-term average.
The price of gasoline may have helped retailers. During the week ending Monday, the national average price of a gallon of unleaded dropped by 4.4 cents to $3.696 a gallon, the U.S. Energy Information Administration said.
Swim Week Miami Beach 2014 [PHOTOS]