This dataset is associated with the article "Spatial Variability of Marine Heatwaves in the Chesapeake Bay". The data contain characteristics and long term trends of marine heatwaves in the Chesapeake Bay, calculated using the included Geo-Polar Blended Sea Surface Temperature (SST). Also included are the source SST datasets and in situ data used for satellite SST validaion. Included satellite datasets are: NASA Multi-scale Ultra-high Resolution (MUR) SST, NOAA Geo-Polar Blended SST, and Copernicus Marine Operational Sea Surface Temperature and Ice Analysis (OSTIA). In situ data is provided by the Chesapeake Bay Program. These datasets are co-located for validation and subset to the Chesapeake Bay to enable more regionally focused analyses. The time period for all observations is January 1, 2003 - December 31 2023.