Highest Islip employee salary in year 2022 was $186,865. Islip employees number in year 2022 was 1,149. Islip average salary was $44,782 and median salary was $46,724. According to the last payroll, Islip average salary is 40 percent lower than USA average and 23 percent lower than New York state average. Islip employee salaries are usually between $7,837 and $71,228. Top 10% of highest-earning employees have salaries ranging from $90,830 to $186,865.