Holiday sales increased 3.8 percent: The National Retail Federation

Tough times for retailers

Holiday sales increased 3.8 percent to $601.8 billion in November and December, according to The National Retail Federation.

This number falls just shy of the group's forecast that sales would rise 3.9 percent to $602.1 billion.

The report follows releases from a wide range of retailers that the holiday season missed their expectations.

In 2012, holiday spending also fell shy of estimates, rising 3 percent as economic uncertainty led to cautious spending among consumers, the retail group said at the time.

This is the second year holiday retail sales have fell short of estimates. The last year retailers beat the NRF's estimate was 2011.

—By CNBC's Katie Little. Follow her on Twitter @KatieLittle