A Langmuir adsorption model is used to represent the conditions at which structure H hydrates may form. The two smaller cavities of structure H hydrates are of similar size and are modeled using the same Langmuir constants. Parameters in a simple two-parameter Langmuir expression have been estimated for methane and nitrogen as guest molecules of the smaller cavities and for 12 possible guest molecules of the large cavity. The latter ones are all hydrocarbons with from 5 to 8 carbon atoms. Experimental hydrate formation temperatures are correlated with an average absolute temperature deviation of 0.15 K. Hydrate formation data for two ternary mixtures not used in the parameter estimation are modeled with approximately the same accuracy.