US consumers are likely to spend $89 billion shopping online during the holiday season, a healthy rise despite fewer selling days, Forrester Research analysts said Monday.

The rise for 2014 is expected to be 13 percent, despite a late Thanksgiving, which shortens the traditional gift-giving season, Forrester analysts said.

"Shoppers turn to the web during the time-pressed period between November and December to avoid crowds, lines, and, in many cases, higher prices," said Forrester's Sucharita Mulpuru,

"This holiday season, e-commerce will experience a boom... as seasoned online consumers are growing more comfortable and reliant on the practice."

Mulpuru said the sales rise and short span between Thanksgiving and Christmas will strain the delivery networks that get packages out to consumers.

"With the expected 13 percent increase in e-commerce sales in 2014 for the months of November and December as compared to the same period in 2013, retailers and consumers must recognize the risk of shipping delays," she said in a blog post.

The National Retail Federation said last month it expects overall holiday sales this year to rise to $616.9 billion, a 4.1 percent increase from last year's level.