U.S. consumer prices rose in January, advancing for the first time since July as energy costs rebounded, government data showed on Friday, but a severe economic downturn was likely to keep inflation pressures muted in the months ahead.

The Labor Department said its closely watched Consumer Price Index rose 0.3 percent after falling 0.8 percent in December. Analysts polled by Reuters had forecast headline CPI rising 0.3 percent.

Core prices, which exclude food and energy items, rose 0.2 percent after being flat in December. That compared to analysts' prediction for a 0.1 percent increase.

On a year-over-year basis, consumer prices were flat, the weakest reading since August 1955. The index rose 0.1 percent year-on-year in December.

Energy prices rebounded 1.7 percent in January, reversing five months of declines. However, compared to the same period last year, energy prices tumbled 20.4 percent.

(Reporting by Lucia Mutikani, Editing by Andrea Ricci)