These are merged lake-effect data stemming from TSI (Suriano and Leathers, 2017) and SSC (Ellis et al., 2021) approaches as outlined in the manuscript under review in the journal "Frontiers in Water" (Ellis and Suriano, 2021).There are two FILES containing dates of lake-effect days for the eastern Great Lakes region (effects from Lakes Erie and Ontario), November 1964 through April 2015.