Factors influencing the solubilities of a large number of gases in water at 298.15 K and 101325 Pa partial pressure of gas have been examined. (For purposes of this article gases are considered to be compounds having normal boiling points below 298.15 K) Since the solubility of these solutes in water range over 7 orders of magnitude and the gases examined include both gases that are chemically inert and gases that react with water, it was not possible to find a single correlation to adequately cover all of them. Accordingly, the gases were grouped into compatible classes, such as chemically reactive, inert, permanent, hydrocarbons, halogen-containing gases, etc. Reasonable correlations with gas solute properties were generally found within each class of compounds.