Unemployment Rate in Mercer County, NJ was 4.30% in February of 2024, according to the United States Federal Reserve. Historically, Unemployment Rate in Mercer County, NJ reached a record high of 11.60 in July of 2020 and a record low of 2.40 in April of 2019. Trading Economics provides the current actual value, an historical data chart and related indicators for Unemployment Rate in Mercer County, NJ - last updated from the United States Federal Reserve on May of 2024.