Consumers once again proved unflappable in the face of high energy prices as a late December shopping spree capped off another successful holiday season. According to the National Retail Federation, retail industry sales (which exclude automobiles, gas stations, and restaurants) for December increased a strong 5.7% unadjusted over last year and were flat seasonally adjusted from the previous month.

Combined, November and December brought holiday sales growth to 6.4%, slightly higher than NRF’s forecast of 6.0%. After all receipts were tallied, consumers spent a total of $438.6 billon this holiday season.

“This was clearly more than just a ho-hum holiday season as some have prematurely reported,” said NRF Chief Economist Rosalind Wells. “Thanks to a last minute surge in spending, fueled in part by gift cards, consumers gave retailers a reason to cheer.”

December retail sales released today by the U.S. Commerce Department show that total retail sales (which include non-general merchandise categories such as autos, gasoline stations and restaurants) rose 0.7% seasonally adjusted from November and increased 6.4% unadjusted year-over-year.

Several retail sectors in December saw strong year-over-year growth. Building material and garden equipment and supplies stores saw positive gains, with sales up 8.2% over 2004. Due to aggressive pricing and clearance promotions, sales at clothing and clothing accessories stores increased 7.6%. Electronics, led by high-demand merchandise such as I-Pods and X-Box 360s, also performed well in December. Sales in electronics and appliance stores increased 7.0%.

Additionally, strong year-over-year gains were seen at health and personal care stores (6.8%), furniture and home furnishing stores (5.6%) and sporting goods, hobby, book and music stores (4.4%).

Sales at department stores, which were challenged by discounters and luxury retailers this holiday season, were down 3.0% from December 2004.

“While 2005 ended on a very positive note, we certainly expect to see a more challenging sales environment in the New Year,” said Wells.