The average custodian salary at Modesto was $77,252 , which is 5 percent higher than the average salary for this job in California, and 9 percent higher than the national average for this job . Custodian salaries at Modesto typically range from $71,636 to $82,868 (25th to 75th percentile). The highest reported custodian salary was $82,868. There are 2 employees at Modesto with the job title custodian.