<p>Ground level ozone is a harmful air pollutant to humans and is not directly emitted. It is formed from the combination of nitrogen oxides (NO_x) and volatile organic compounds (VOCs) in the presence of warm temperatures and sunlight. The St. Louis metropolitan area is home to different types of industry and the citizens of the area rely on the interstate network to commute to and from work. A spatial analysis of the St. Louis metropolitan area's 2012 ozone season (April 1 - October 31) was conducted to investigate the relationships between ground level ozone and meteorological and climatological variables at the micro- and synoptic scales. Previous studies addressed these relationships but may not have accounted for the issue of autocorrelation. The some of the study variables experienced autocorrelation; however, by calculating the effective sample size the issue of autocorrelation was addressed. High maximum temperatures, little to no precipitation, low average wind speeds at the surface, coupled with dominant anticyclones/high pressure and little moisture aloft were found to be associated with the 40 days during which Federal ozone exceedances occurred. The days with the most exceedance were Fridays (8) while the fewest were observed on Sundays (3). Like most summers, the greatest number of exceedance days occurred during the month of July (16). Precursors to ozone, and persistent ozone itself, also led to extended periods of high ozone. All of these factors, combined with emissions from vehicles and from industry, led to days on which the surface air quality may have been detrimental to human health.