The ICSC-Goldman Sachs weekly tracking report indicated sales rose "a solid" 1.4 percent from the previous week and 2.1 percent from the same week of 2012.
The weekly report said summer clearance sales and hot weather prompted a robust week in retail.
Gasoline prices were little changed in the week, dropping a "marginal 0.4 cents" per gallon to a national average of $3.492 Monday, the Energy Information Administration said.
"Summer clearance sales continued to be the prime mover for sales -- especially helped this past week by a bout of excessive heat in the Northeast and parts of the Midwest -- and those sales will remain the prime mover until back-to-school shopping kicks in more aggressively in August.," ICSC Vice President of Research and Chief Economist Michael Niemira said in a statement.
The trade group predicted sales would rise 3-3.5 percent for the fiscal month of July after a gain of 4.1 percent in June.