The aim of this paper is to present the results of mathematically modelling the influence of ambient temperature on hydrocarbons (HCs, comprised of methane and non-methane volatile organic compounds) in cold-start emissions from passenger cars (PCs) for different fuel types, vehicle segments including hybrid vehicles, and the Euro standard. In this article the simulations are performed using COPERT software, assuming ambient temperatures from 20◦C to +30◦C, with 5◦C intervals. The modelling results presented show that a change in ambient temperature has a significant effect on hydrocarbons in cold-start emissions. Furthermore, our results show that hydrocarbons emissions are sensitive to ambient temperature fluctuations, and dependent on fuel type, vehicle segment, and the Euro standard.