Nonfarm payroll employment rose just slightly in January but the nation’s unemployment level fell to 9%. The Labor Department‘s Bureau of Labor Statistics said the economy added 36,000 jobs during the first month of 2011 with gains in manufacturing and retail. Employment levels fell in the construction, transportation and warehousing sectors with little change in most other industries. Lots of poor winter weather and annual benchmark revisions to the data hurt jobs growth in January. After climbing to 9.8% in November, the unemployment rate decreased to 9.4% in December. Despite another decline in the rate for January, jobs growth came in well below most estimates. Analysts surveyed by Briefing.com were expecting an increase of 125,000 jobs for January. The consensus figure from an Econoday survey forecast 150,000 new jobs with a range of estimates between gains of 55,000 and 200,000. Lots of disruptive winter weather and annual benchmark revisions to the data hurt the level of jobs growth in January. Data from the latest survey reflect updated population estimates from the Census Bureau. The number of unemployed Americans fell by about 600,000 last month to 13.9 million, and nearly 44% of those without jobs have been unemployed for 27 weeks of more, according to the Bureau of Labor Statistics data. The number of people “marginally attached to the labor force” climbed to 2.8 million in January from 2.5 million. Most of these are people ready, willing and able to work but haven’t looked for a job in the month prior to the Labor Department’s most-recent survey. Although 1 million of them are classified as discouraged workers, who aren’t searching for a new job “because they believe no jobs are available for them.” On Wednesday, Automatic Data Processing Inc. said the private sector added 187,000 jobs in January, up from a revised increase of 247,000 jobs for the final month of 2010. Initially ADP, which conducts the monthly survey in conjunction with Macroeconomic Advisers, said private-sector employment rose by a record 297,000 jobs in December. It was the largest monthly gain since ADP began tracking the data in 2000. Some analysts and market watchers, including Macroeconomic Advisers, raised a suspicious eye toward the ADP data for December. Then earlier this week, one economist wondered what kind of gauge the ADP figures are in relation to the federal nonfarm payroll data. Capital Economics Chief U.S. Economist Paul Ashworth questioned if the ADP survey “can be trusted” to provide an accurate indication of the federal data. His firm projected nonfarm payrolls to add 125,000 in January. Write to Jason Philyaw.