Highest salary at Jefferson County in year 2020 was $172,576. Number of employees at Jefferson County in year 2020 was 498. Average annual salary was $27,054 and median salary was $26,769. Jefferson County average salary is 42 percent lower than USA average and median salary is 38 percent lower than USA median salary. From 2019 to 2020, the average salary of employees at this employer increased 5.9 percent, the median salary increased 9.2 percent.