These data are associated with experiments performed in 2016 and 2017 in the Fox rivermouth (Green Bay, WI; Lake Michigan). Between the De Pere Dam and the Lake Michigan coastline, we performed experiments to measure water column transformation of dissolved organic matter (DOM) and sediment flux of DOM. These experiments consisted of incubations of surface water or intact sediment cores and repeated measures over time of DOM concentration and optical properties. When these experiments were performed, we also measured inorganic nitrogen and phosphorus dynamics. Results and data related to nitrogen and phosphorus have already been published. We also measured ancillary environmental data that would assist in understanding variation in DOM dynamics (e.g., incident solar radiation, water temperature, etc.). Using these data, we then modeled the overall change in DOM that is occurring in the Fox rivermouth.