Without the temporary hiring of Census workers, the disappointing August jobs report would have been even worse.

The federal government hired 25,000 temporary workers in preparation for the 2020 Census in August, giving the overall jobs gain a big bump. Nonfarm payrolls increased by 130,000 last month, which fell short of Wall Street estimates for 150,000.

Employment in federal government rose by 28,000 in total in August, the Labor Department said Friday. Private-sector employment was up by only 96,000, the lowest pace since February.

The weakness largely came from the retail sector, which saw a net decline in workers of 11,100 in August alone. Trade, transportation and utilities also lost 11,000 jobs, and mining and logging lost 5,000 positions.

"The weaker than expected job gains do make sense when looking at yesterday's ISM and Markit figures on employment and just understanding how businesses respond to the slowing pace of growth and trade worries," said Peter Boockvar, chief investment officer at Bleakley Advisory Group. "Companies have taken a time out on hiring until visibility becomes less cloudy, it's only prudent."

The ISM gauge of U.S. manufacturing showed the sector contracted in August, its first decline since 2016.

The overall labor market is still in good shape. The unemployment rate stayed at 3.7% as expected, and wage growth remained strong, with average hourly earnings increasing by 0.4% for the month and 3.2% over the year.

Beside the big job additions ahead of the 2020 population count, professional and business services also added 37,000 jobs. Health care contributed 24,000 to the total number and financial services rose by 15,000.

—CNBC's Jeff Cox contributed reporting.