Highest salary at St Charles County in year 2023 was $200,675. Number of employees at St Charles County in year 2023 was 1,045. Average annual salary was $58,707 and median salary was $56,542. St Charles County average salary is 25 percent higher than USA average and median salary is 30 percent higher than USA median salary. From 2022 to 2023, the average salary of employees at this employer increased 3.0 percent, the median salary increased 4.8 percent.