The National Retail Federation reported that sales for the 2015 holiday retail season inched up 3 percent to $626.1 billion compared with the holiday season in 2014.

The recent results, announced Jan. 15, were down slightly from the NRF’s preseason prediction. The retail trade group, based in Washington, D.C., had expected sales to climb 3.7 percent. During the 2014 holiday season, sales showed a more robust 4.1 percent increase.

However, NRF President and Chief Executive Matthew Shay called the 2015 results solid. “While some will attempt to diminish this positive outcome, the fact remains that retail continues to play an important role in growing our economy,” he said. “This holiday season has proven once again that the industry can quickly and successfully respond to a rapidly changing and challenging sales environment in order to achieve continued year-over-year growth.”

Temperatures for the holiday season were unseasonably warm across the United States. Economists and executives blamed the balmy weather for shoppers postponing purchases of things such as outerwear, gloves and boots.

Terry J. Lundgren, chairman and chief executive officer of Macy’s Inc., specifically blamed the warm weather for Macy’s recent soft performance. “About 80 percent of our company’s year-over-year declines in comparable sales can be attributed to shortfalls in cold-weather goods such as coats, sweaters, boots, hats, gloves and scarves,” he said before announcing the department-store giant would close 40 Macy’s stores across the country.

Store closures also have hit other major retailers. On Jan. 15, Wal-Mart Stores Inc. announced it would close 269 stores in the U.S. and around the world. In California, the company will close stores in San Jose, downtown Long Beach and on Crenshaw Boulevard in Los Angeles.

The U.S. Department of Commerce released retail sales numbers for all categories on Jan. 15. December retail and food services sales were $448.1 billion, down 0.1 percent from the previous month but 2.2 percent above December 2014.

The 2016 winter holiday season was hobbled by retailers offering deep discounts early in the season, said Marshal Cohen, chief industry analyst for NPD Group, a prominent market-research company. In a Jan. 21 blog, Cohen wrote, “Earlier promotions may bring earlier shopping, but that doesn’t ensure greater sales results in total. Retailers need to do a better job of pacing the holiday, putting sales in place at strategic and necessary times, rather than the shotgun approach we have seen for the past few years.”