Technical Abstract: Drift from aerial application of crop protection and production materials is influenced by many factors for which the applicator is responsible for considering and adjusting, where applicable, to reduce as much as possible, the potential drift. In an effort to study the uncontrollable factors, this study monitored and documented atmospheric conditions over the course of several months at two locations in Texas. The measured meteorological data was used to assess how atmospheric stability varied as a function of time of date, location, and other meteorological conditions. Additionally, inversion periods were examined for strength, time of occurrence, and duration. Stable and very stable atmospheric conditions, which would tend to produce the most drift, primarily occurred between the hours of 6 p.m. and 6 a.m., with a few occurrences between 6 a.m. and 6 p.m. Between the hours of 6 a.m. and 6 p.m. unstable atmospheric conditions tended to be dominate. Of the days monitored, almost half experienced inversion periods between the hours of 6 a.m. and 6:30 p.m., with more than half of these inversion periods being after 4 p.m. and having durations an order of magnitude greater than periods of inversions seen between 6 a.m. and 4 p.m. Generally, these late afternoon periods are of most concern as the probability of experiencing increasingly stable conditions or long inversion period increases.