The average custodian salary at Napa was $112,803 , which is 55 percent higher than the average salary for this job in California, and 59 percent higher than the national average for this job . Custodian salaries at Napa typically range from $103,353 to $125,195 (25th to 75th percentile). The highest reported custodian salary was $125,195. There are 3 employees at Napa with the job title custodian.