These data are a compilation of geographically widespread observations of premature mortality in Pacific salmon across their range in Alaska in 2019. Premature mortality observations primarily spanned an area of western and southcentral Alaska that is approximately one million km2 and included all five species of Pacific salmon. Observations were obtained and compiled in a single database from four sources including reports to a citizen science reporting network (LEONetwork.org), from Alaska Department of Fish and Game's Arctic-Yukon-Kuskokwim region by community members or staff, traditional media and social media, and directed emails by the lead author. Occasional observations of species other than Pacific salmon were obtained during this effort and were included in the database.