Air water partitioning of all nine C5 and C6 isomeric alkanones (namely, pentan-2-one, pentan-3-one, 3-methylbutan-2-ne, hexan-2-one, hexan-3-one, 3-methylpentan-2-one, 4-methylpentan-2-one, 2-methylpentan-3-one, and 3,3-dimethylbutan-2-one) in water was examined at several temperatures in the range from (273 to 333) K using the inert gas stripping technique. Results are reported in the form of air water partition coefficients K-aw and limiting (infinite dilution) activity coefficients gamma(infinity)(1) A comprehensive critical review is further presented for such literature data as well as data on respective derivative thermal properties (enthalpies and heat capacities of hydration and dissolution). For each alkanone, the data measured in this work together with those reported previously in the literature were correlated with a suitable model equation providing an adequate simultaneous description of the equilibrium measurements and the calorimetric information. As a result, recommended K-aw(T) and gamma(infinity)(1) (T) temperature dependences of superior accuracy were established. The variation of K-aw and gamma(infinity)(1) ith temperature and alkanone molecular structure was briefly discussed. Furthermore, the performance of seven predictive approaches to estimate K-aw(T) and gamma(infinity)(1)(T) of the alkanones was tested.