December's figure was revised to 652 thousand units from 621 thousand previously estimated.
New home sales went down in the South (-15.1 percent to 342 thousand), the Midwest (-28.6 percent to 50 thousand) and the Northeast (-11.4 percent to 31 thousand) but rose in the West (27.8 percent o 184 thousand).
The median new house price fell to USD 317,200 in January from USD 319,100 in December and USD 329,600 a year ago. The average sales price dropped to USD 373,100 from USD 374,000 in December and USD 377,800 a year ago.
The stock of new houses for sale went down 1.5 percent to 336 thousand from 341 thousand in December. This represents a supply of 6.6 months at the current sales rate, down from 6.3 months in December.
Year-on-year, new home sales decreased 4.1 percent.