Version 1.1 of MPRM (Meteorological Processor for Regulatory Models) provides a general purpose computer processor for organizing available meteorological data into a format suitable for use by air quality dispersion models. Specifically, the processor is designed to accommodate those dispersion models that have gained EPA approval for use in regulatory decision making. MPRM can be envisioned as a three stage system. The first stage retrieves the meteorological data from computer tape or disk files and processes the data through various quality assessment checks. The second stage collects all data available for a 24-hour period (upper air observations, hourly surface weather observations, and data collected as part of an on-site meteorological measurement program) and stores these data in a combined (merged) format. The third stage reads the merged meteorological data and performs the necessary processing to produce a meteorological data file suitable for use by the specified dispersion model.