Estuarine environments are characterized by strong spatial gradients and high temporal variability that are difficult to fully capture with discrete field measurements. This is particularly the case in the Chesapeake Bay, the largest estuary in the continental United States. This archive provides a climatological atlas of physical and biogeochemical conditions for the Chesapeake Bay based on numerical model results of 1985-2023. The atlas includes surface and bottom conditions on a fine longitude/latitude grid with a monthly frequency. The environmental variables are stored in a NetCDF file with abundant metadata that can be used in software such as QGIS, Python, R, Matlab or GNU Octave. A 50+ page documentation in PDF format provides additional information on the environmental variables, the numerical model used to generate the climatology, and an evaluation of the model skill over the period of the atlas. The documentation also includes ready-made visualizations for each environmental variable.