Deterministic diffusion-kinetic modeling has been performed to calculate the temperature dependence of the radiation chemical yields (G-values) of the radiolysis products of water. The FACSIMILE numerical method has been used to solve a set of coupled differential equations describing the diffusion and reactions of the species for the temperature range 20-300 degrees C. The low LET spherically symmetrical case of an "average" spur with 62.5 eV deposited in it has been considered. Modeling calculations have been compared for Gaussian, an exponential distribution, and a distribution with a central minimum assumed as the initial spatial distribution of the hydrated electron (e(aq)(-)). In all cases spatial distributions of the other radiolytic products started as Gaussian. To fit the experimental data it has been necessary to assume that the reaction e(aq)(-) + e(aq)(-) --> H-2 + 20H(-) becomes diffusion controlled at elevated temperatures and to include a contribution of 13% to the initial yields of water decomposition through the dissociation of electronically and vibrationally excited molecules : H2O --> H + OH (I) and H2O --> H-2 + O(D-1) --> H-2 + 20H (or H2O2) (II). The products of these processes are considered to be correlated in space. Good accord with experiment is achieved with the total contributions of I and II being independent of temperature but with their ratio decreasing from ca. 21:1 to ca. 4:1 with increasing temperature above 220 degrees C. For process I calculations predict a temperature dependent probability of cage recombination of H + OH. For process II slightly better agreement is obtained with the solvolysis of O(D-1) producing H2O2 instead of a caged pair of OH’s.