A physical-mathematical model for describing the propagation of liquid-droplet components of the rocket propellant in areas of falling the launcher separated units is presented. The model was developed with accounting for the real weather conditions. The results of calculation of the asymmetrical dimethylhydrazine droplet cloud evolution, formed at the second stage of "Proton-K" launcher separation above the Tomsk Region at starts from Baikonur Cosmodrome on October 26 and December 26, 2007, are analyzed.