The U.S. Geological Survey New England Water Science Center, under an interagency agreement with the Federal Emergency Management Agency, conducted frequency analyses of stillwater elevations at three National Oceanic and Atmospheric Administration coastal gages following the coastal floods of 2018. The datasets are comma-delimited files of period-of-record annual peak stillwater elevations collected at gages in Boston, Massachusetts, Portland, Maine, and Seavey Island, Maine, for analysis of annual-exceedence probabilities. The peak water-surface elevations are in feet in the North American Vertical Datum of 1988.