This dataset is accompanying the submission of the manuscript "Silica polymerization and nanocooloid nucleation and growth kinetics in aqueous solutions". It contains experimental data describing the concentration of aqueous monomeric silica as a function of time. The experimental conditions (temperature, pH, ionic strength) are also given. These data were used to fit the rate constants using the fourth-order rate kinetic expression described in the paper. Data are provided as an Excel file.