[en] Hourly solar irradiation data of Montreal are analyzed. Eleven-year (1964-75) monthly average values of the ratio hourly/daily of the global as well as the diffuse irradiation on a horizontal plane are plotted against the solar time for each of the 12 months. The normal distribution curve recently suggested by the author for analysing the hourly global irradiation data of Trieste, is found to fit both the data fairly well. The mean of the normal curve is taken at the solar noon. The σ values are obtained by matching the experimental and the theoretical values at the solar noon. These σ values are found to be related to S-bar_o by the equation σ=0.209 S-bar_o + 0.294 for the global irradiation and by the equation σ=0.222 S-bar_o + 0.270 for the diffuse irradiation, with excellent coefficients of correlation. The technique is simple, fairly accurate and appears to be universally applicable