This paper reports three-phase (ice + vapor + clathrate hydrate) equilibrium conditions in methane + water system at temperatures between 197.3 K and 238.7 K. These equilibrium condition data could be applied for utilization of methane clathrate hydrate as a natural gas transportation medium, a working medium for heat pump/power generation cycles, and to further our understanding of the environments of planets and satellites. The equilibrium conditions were measured using the isochoric procedure. The measured equilibrium pressures are from 111.7 kPa at 197.3 K to 794.1 kPa at 238.7 K and increase with an increase in temperature. The internal consistency of the measured equilibrium data are examined by applying the Clausius-Clapeyron equation. Discussion is given on the comparison of the equilibrium data measured in this study to those reported in the literature. (C) 2016 Elsevier Ltd.