Highest salary at Essex County in year 2017 was $188,147. Number of employees at Essex County in year 2017 was 506. Average annual salary was $41,857 and median salary was $42,299. Essex County average salary is 11 percent lower than USA average and median salary is 3 percent lower than USA median salary. From 2016 to 2017, the average salary of employees at this employer increased 3.7 percent, the median salary increased 8.6 percent.