Whatcom County’s unemployment rate dropped from 5.7 percent in August to to 5.4 percent in September, according to the newest monthly report from the state Employment Security Department.

Most of the new jobs were in construction, according to the report.

Whatcom County had a 5.4 percent unemployment rate this April but the rate rose throughout the summer, hitting a peak of 6 percent in July.

The rate is down almost a full percentage point from last September, when it was 6.3 percent. Since then, the construction sector has grown the fastest, with the professional and business services, and leisure and hospitality sectors coming in at a close second and third.

In total, the county gained 2,400 nonfarm jobs in the last year, 2,000 of those are in the private sector and 400 are in government, according to the report.

The county’s civilian labor force — the number of people 16 and older who are not in the military and either have a job or are seeking a job— grew by 518 people to 100,047 in the last year.

The state’s seasonally adjusted unemployment rate dropped from 5.3 in August to 5.2 in September. The county numbers from the Employment Security Department are not seasonally adjusted and therefore should not be compared directly to the statewide rate, the department warns.

San Juan County had the lowest unemployment rate in the state in September, at 3.8 percent. King County’s rate was 3.9 percent. Ferry County, in northeast Washington, had an unemployment rate of 9.1 percent, the state’s highest.