The solubility of methane was measured in brines at temperatures from 0 to 300 deg c by the technique of gas extraction. Results, expressed in terms of the henry's law constant, were fit to a smoothing and interpolation formula for subsequent interpretation and analysis. The results can be extrapolated to temperatures above 300 deg c. The henry's law constant exhibits maximums in the temperature range 80 deg to 100 deg c. Methane is salted out with increased concentration of dissolved salts. The salting-out coefficient is strongly dependent upon temperature. The effect of temperature on solubility in a hypersaline geothermal brine is different from that for the simpler sodium chloride brines owing to the more complex chemistry of the geothermal brine.