U.S. businesses added 74,000 jobs in December, well below the 200,000 that were forecast. The details also look weak, but the good news is that some of the drag looks temporary and January job growth should bounce back. What can be gleaned from Friday's report:

 

1.   Blame Mother Nature

Construction—one of the industries most affected by weather—reported a loss of 16,000 jobs, the first drop since June and the biggest decline since May 2012.

2.   Less of the population is working or looking for work

The unexpected drop in the December jobless rate to 6.7%—the lowest since October 2008—reflects a decline in the number of unemployed. Where did those people go? Less than one-third found work; the rest dropped out of the labor force.

3.   Health-care hiring takes a sick day

The health-care sector cut 6,000 positions in December. That's the first seasonally adjusted drop since the Labor Department started tracking this sector in 1990, and reflects a sharp slowdown in the unadjusted number of hires—only 1,800 jobs added last month, compared with a 27,000 average in the previous five Decembers. Much like the weather effect, however, the slowdown is probably a one-off event and hiring should rebound in January.

4.  Look for a small December income gain

The weak payroll number was accompanied by a shorter work week and little change in hourly pay. The workweek fell six minutes to 34.4 hours in December. Hourly pay for all employees increased only 2 cents, or 0.1%, to $24.17, less than the 0.2% gain forecast. That combination suggests wages and salaries hardly grew last month.

5.   Jobless rate creates a problem for Fed officials

The central bank has said it wouldn't consider raising short-term interest rates until unemployment reaches the 6.5% threshold; now, it's just 0.2 percentage point away. Fed officials know the decline isn't all because of a healthy labor market, and they don't want to start tightening credit too quickly after the jobless rate gets to 6.5%.

—Kathleen Madigan