Highest salary at Jefferson County in year 2018 was $183,000. Number of employees at Jefferson County in year 2018 was 1,020. Average annual salary was $42,452 and median salary was $42,264. Jefferson County average salary is 9 percent lower than USA average and median salary is 3 percent lower than USA median salary. From 2017 to 2018, the average salary of employees at this employer increased 3.4 percent, the median salary increased 0.6 percent.