During summer 2000, Baylor University staff flew a Twin Otter aircraft for 33 flights to collect a unique set of morning and afternoon aloft air quality data in the Houston–Galveston Bay area. For this work, we present the spatial characteristics of the aloft ozone, total reactive nitrogen (NO_y), sulfur dioxide (SO₂), and volatile organic compounds (VOCs) collected by the aircraft and investigate the relationship between ozone and its precursors, including the chemical structure of VOCs observed along with the peak ozone concentrations. These characteristics are presented in context of the observed meteorological conditions, including the land/sea breeze circulation and the evolution of the planetary boundary layer. These results provide the foundation needed to develop a more comprehensive understanding of the processes that influence ozone air quality in the Houston–Galveston area. Additionally, the results can be used to support photochemical modeling efforts.