The county's jobless rate in October was 6.4 percent, down from 6.9 percent the previous month.
It's Whatcom County's lowest monthly rate since December of 2008.
Regional Economist Elizabeth Court with the state Employment Security Department says the county saw job growth over the previous month in every sector except leisure and hospitality, which she says is typical after the summer.
She says the jobless rate also typically drops in October as retailers hire more people ahead of the holidays.
Whatcom County's unemployment rate is still lower than many neighboring counties.
In Snohomish County, October's unemployment rate was 7.1 percent.
Skagit County had a jobless rate of 8.1 percent in October.