The energy of low electronic states of monomer and dimer water complexes, H2O and (H2O)2, has been calculated. It is shown that KrF–laser–induced photoabsorption of water vapor may be accounted for by the transitions from hot rovibrational levels to quasicontinuum of H2O states, whereas the fluorescence may be explained by the recombination of the products of monomer water complex disintegration.