WASHINGTON — U.S. consumer prices rose 5.7% in the past year, the fastest pace in 39 years, as a surge in inflation confronts Americans with the holiday shopping season under way.

The November increase, reported today by the Commerce Department, followed a 5.1% rise for the 12 months ending in October and kept up a trend of annual price gains running well above the 2% inflation target set by the Federal Reserve.

Thursday’s report showed that consumer spending, which accounts for 70% of economic activity, rose 0.6% in November, a solid gain but below the 1.4% surge in October.

Personal incomes, which provide the fuel for future spending increases, rose 0.4% in November, slightly lower than the 0.5% increase in October..

The big jump in the Commerce Department’s price gauge was similar to the rise in the consumer price index, which was up 6.8% for the 12 months ending in November, also the biggest surge by this measurement in 39 years.