Experimental data are presented for methane hydrate stability conditions in seawater (S≈33.5%). For the pressure range of 2.75--10.0 MPa, at any given pressure, the dissociation temperature of methane hydrate is depressed by approximately -1.1ℏ relative to the pure methane-pure water system. These experimental results are consistent with previously reported thermodynamic predictions and experimental results obtained with articifical seawater. Collectively these results provide a minimum constraint concerning depth ranges over which methane hydrate is stable in the oceanic environment. ¿ American Geophysical Union 1994