BLS metro-level wage data places Stationary Engineers and Boiler Operators pay in St. Louis, MO-IL at a median of $75,610 per year ($36.35/hr/hour), drawn from the OEWS May 2025 release for this Metropolitan Statistical Area. Compared to the national median of $78,620, St. Louis pays 4% below, which typically tracks with a lower local cost of living or smaller specialized-employer cluster. Approximately 240 stationary engineers and boiler operatorss are employed across the St. Louis MSA in SOC 51-8021.

The St. Louis pay distribution spans from $61,570 at the 10th percentile to $96,730 at the 90th — a 1.6× spread that reflects experience tenure, specialization, employer size, and the difference between public-sector, nonprofit, and private-sector compensation inside the metro. The 25th percentile sits at $66,650 and the 75th at $85,070, so half of St. Louis-based stationary engineers and boiler operatorss earn within that middle band.

Metro figures capture where you actually work, not just where you live — which matters for commuters. BLS draws metro boundaries from the OMB MSA definitions, so St. Louis, MO-IL covers the central city plus outlying counties tied to the metro economically. Remember that OEWS wages reflect base pay only: employer-provided health insurance, retirement matches, stock options, signing bonuses, overtime, and tips are excluded and can add 20-40% to real total compensation. Before using this metro median as a negotiation anchor, triangulate against the same occupation's national profile (linked below), its state-wide MO data, and peer-metro comparisons — a median is a starting point, not a ceiling.