According to data from the US BLS, the unemployment rate of New Hampshire was 2.8% (sa) in December, 2017. Among all New Hampshire counties, these 3 were among those with high unemployment rates (nsa): Coos (3.3%), Rockingham (2.7%), and Hillsborough (2.6%).

On the hand, the following three counties were among those with low unemployment rates (nsa): Grafton (2%), Sullivan (2.1%), and Merrimack (2.1%).

The chart and table below shows the unemployment rate (nsa) for each county.

You can see similar information by state for the United States.