Nitrocellulose propellants represent the dominant type of propulsive explosives in modern military and civilian use, whereby their chemical stability during long-term storage remains a critical factor for safety and operational reliability. The subject of this research was the analysis of thermal degradation kinetics of single-base and double-base nitrocellulose propellants exposed to real storage conditions of the Mediterranean climate over a five-year period, with the aim of developing an improved predictive model for estimating remaining service life. The research encompassed continuous monitoring of temperature and hygrometric parameters in three representative storage facilities on the Adriatic coast, along with periodic sampling and laboratory analysis of propellant samples using differential scanning calorimetry methods, Fourier transform infrared spectroscopy, vacuum stability testing, and high-performance liquid chromatography. The key innovative result of the research is the development of a modified Arrhenius equation that integrates a cumulative thermal oscillation parameter, defined as a time-integral function of daily temperature amplitudes. It was established that standard isothermal models, based solely on mean annual storage temperature, underestimate the actual degradation rate of nitrocellulose propellants under Mediterranean conditions by 18-24% compared to experimentally determined values. The new model, designated as MTOD (Mediterranean Thermal Oscillation Degradation), demonstrated a coefficient of determination R² = 0.967 in predicting the residual content of the stabilizer diphenylamine, which represents a significant improvement compared to conventional isothermal models with R² = 0.891. The research results imply the need for revision of existing NATO STANAG standards for ammunition service life assessment in climatic zones with pronounced temperature oscillations