The Commerce Department said Thursday retail sales fell 0.4 percent last month, led by a drop in automobile sales.
Economists polled by Reuters had forecast retail sales unchanged in January.
Sales in December were revised to show a 0.1 percent fall instead of the previously reported 0.2 percent rise. The second month of declines in sales likely reflected frigid temperatures across many parts of the country.
"The weakness we saw in retail sales is unfortunately weather-related and we are clearly seeing that the first quarter growth is slower than we anticipated," said Peter Cardillo, chief market strategist at Rockwell Global Capital in New York.
"But I still don't think this data is trend changing."
Stocks opened lower following the retail sales figures.
Stripping out automobiles, gasoline, building materials and food services, so-called core sales fell 0.3 percent after rising 0.3 percent in December.
Core sales correspond most closely with the consumer spending component of gross domestic product. Economists had expected this category to advance 0.2 percent in January.
In a separate report, the Labor Department said initial claims for state unemployment benefits rose 8,000 to a seasonally adjusted 339,000 in the week ended Feb. 8.
Economists polled by Reuters had forecast first-time applications for jobless benefits slipping to 330,000.
The reports added to data on factory activity and employment in suggesting a loss of steam in the economy this quarter, in part because of the unseasonably cold weather and payback after the brisk 3.7 percent annual growth pace in the second half of last year.
Economists are yet to quantify the effect of the relentlessly freezing temperatures, which have left large parts of the country shivering since December.
Last month, receipts at auto dealers fell 2.1 percent. It was the second consecutive month of decreases. Auto manufacturers complained last week that frigid temperatures had hurt sales.
Retail sales excluding automobiles were flat. Sales of building materials and garden equipment rose 1.4 percent. There were also gains in receipts at electronics and appliance stores.
However sales at clothing retailers and at sporting goods, hobby, book and music stores fell, as did receipts at furniture shops.