Over decadal time scales, water quality in streams often changes due to shifts in land use or climate. Studies that examine shifts in water quality typically quantify changes at annual time scales. Furthermore, some studies report annual findings based on calendar years, while others report water years. For seasonal comparisons, some studies utilize meteorological seasons while others utilize astronomical seasons. Stresses applied on water can have variable effects depending on season (e.g. summer algal blooms) and water quality improvements in one season and a decline in another can be masked if data are only examined at annual scales. In this study, we will be evaluating water quality at various temporal scales to test if annual trends mask significant seasonal changes. This research analyzes 30 years of data from 3 adjacent streams within the Acton Lake watershed in southwest Ohio. We investigate patterns in nitrate (NO3), ammonium (NH4), soluble reactive phosphorus (SRP), and suspended solids (SS) concentrations. We also examine if trends in water quality are consistent between temporal grouping options. For example, for annual comparisons, we compare calendar year vs. water year trends and for seasonal comparisons, we compare meteorological vs. astronomical seasonal trends. This improved understanding can be used to judge where efforts are best spent towards improving water quality and can help to inform future watershed management approaches.