WASHINGTON — Retail sales during 2020’s November-December holiday season grew an unexpectedly high 8.3% over the same period in 2019 to $789.4 billion, according to the National Retail Federation (NRF).

Online and other non-store sales increased 23.9% to $209 billion.

NRF chief economist Jack Kleinhenz said consumers shifted into high gear in December, giving the holiday season a strong finish that could be a good sign for the continuing recovery of the economy this year.

NRF said the 8.3% holiday season increase was more than double the 3.5% average holiday increase over the previous five years, including 2019’s 4% gain.

Retail sales in December were down 1.6% seasonally adjusted from November but up 8.6% unadjusted year over year.

As of December, the three-month moving average was up 8.9% over the same period in 2019.

NRF’s numbers are based on data from the U.S. Census Bureau, which reported that overall December sales — including auto dealers, gas stations and restaurants — were down 0.7% seasonally adjusted from November but up 2.9% unadjusted year over year.