These data were collected at Shannon Point Marine Center in Washington, U.S.A. in March and May, 2021. Embryos were reared at four temperatures in March (10, 12, 14, 16C) and two temperatures in May (10, 16C). In both March and May, embryos were reared at either ~500 pCO2 uatm (ambient) or ~2000 pCO2 uatm (heightened). These data measure the daily and cumulative hatching response of embryos in both March and May.