The popularity of using synoptic climatological approaches to evaluate environmental problems has undergone a recent resurgence, and several objective procedures have been developed. The purpose of this study is to propose an objective methodology to characterize air masses at a given locale and to show that a holistic synoptic approach may provide better results than traditional statistical approaches in evaluating the impact of climate on sulfur dioxide concentrations. The relationships between individual weather variables and sulfur dioxide were weak when they were examined via stepwise multiple regression. The synoptic methodology, using principal components analysis and a clustering procedure, proved more informative. We were able to identify air mass categories exhibiting particularly high sulfur dioxide concentrations and synoptic scenarios of long duration contributing to severe concentration levels. Additionally, those air mass categories most strongly associated with low-level, pollution-inducing inversions were noted. The synoptic procedure should prove helpful in determining if long-term trends in concentration can be attributed to weather conditions or to changes in emissions.