According to data from the US BLS, the unemployment rate of Connecticut was 4.2% (sa) in January, 2018. Among all Connecticut counties, these 3 were among those with high unemployment rates (nsa): Windham (5.6%), New Haven (5.1%), and Litchfield (5%).

On the hand, the following three counties were among those with low unemployment rates (nsa): Middlesex (4.4%), Tolland (4.5%), and Fairfield (4.6%).

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

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