New York City’s unemployment rate took an unusually steep fall for the second straight month, dropping to 6.8 percent in September, its lowest level in nearly six years, the State Labor Department reported on Thursday.

In just two months, the city’s official unemployment rate has declined by a full percentage point, a descent that has brought it much closer to the national unemployment rate of 5.9 percent. Through July, the city’s rate had remained high despite steady increases in the number of jobs. The jobless rate for August was 7.3 percent.

Now it is “more consistent with the strong growth in private-sector employment in the city,” said Elena Volovelsky, an economist with the Labor Department. Over the past year, the number of jobs in the city’s private industry has risen by about 95,000, or 2.8 percent.

The tally of jobs is derived from a monthly survey of employers, while the unemployment rate is calculated from a separate survey of residents. (Only those who say that they tried but failed to find work count as unemployed.) The different methods often lead to results that seem contradictory from month to month, but over longer periods, they should tell a similar tale.