Dataset includes 8 water quality surveys conducted between May and September 2021 at 4 stations in Hamilton Harbour by the Ontario Ministry of the Environment, Conservation and Parks (MECP) staff. The 4 stations surveyed by MECP are Environment and Climate Change Canada’s 4 long-term monitoring stations in Hamilton Harbour and include centre station and the 3 corners of the harbour. During each survey, water quality samples were collected from 1 metre depth and just above the sediment bed. Depth-integrated samples from the upper or surface layer of the lake were also collected at centre station only. Water samples were analyzed for nutrients and related parameters including: * Phosphorus * Nitrogen * Chlorophyll * Suspended solids * Reactive silicate * Carbon In addition, secchi disc depths and water column profiles of temperature, conductivity, turbidity, pH, and dissolved oxygen were also collected at each station.