The average custodian salary at Napa was $89,827 , which is 23 percent higher than the average salary for this job in California, and 26 percent higher than the national average for this job . Custodian salaries at Napa typically range from $66,789 to $112,866 (25th to 75th percentile). The highest reported custodian salary was $121,440. There are 4 employees at Napa with the job title custodian.