In this paper, a spectrum model is constructed where the Boltzmann exponential behavior with carrier temperature variation, band gap energy shift, and the increase in the nonradiative recombination rate with junction temperature are included explicitly. In a first step, an experimental spectrum at a particular temperature is modeled with two exponentials and a Gaussian function, using frequency as the main variable. Afterwards, peak frequency, absolute spectrum power, and spectrum skewness variation with temperature are implemented. The model allows for very accurate simulations of single color LED spectra at any temperature.