The prediction of the temperature rise downwind from a long fire front advantage in the open is of interest in the study of fire spread. This report which extends and revises an earlier report Fire Research Note 510 presents a simplified correlation in terms of dimentionless variables of the experimental data published by Rankine on the effect on the downwind temperature rise of the heat output from a line burner and the wind speed. Despite some variations of temperature rise with the absolute values of the wind spped. Despite some variations of temperature rise with the absolute values of the wind speed and heat output other htan those accounted for by the dimensionless variables, the correlations are on the whole satisfactory.