This study includes a summary of air temperature and relative humidity values that characterize the indoor climate of the "Poni-Cernatescu" Museum in Iași, Romania, over a two-year period. This study presents the evolution of two internal microclimate parameters, air temperature and relative humidity, as well as their correlation with external climate factors, using charts and tabular data. The goal of this study was to describe the museum microclimate as well as to identify and analyze the degradation risk of museum artifacts in order to investigate the impact of hygrothermal indoor and outdoor loads on indoor microclimate parameters. To achieve the goal, the following activities were conducted: data collection on the relative humidity and temperature of indoor and outdoor air; data analysis using climate analysis tools and statistical methods; and data transformation into quantitative and qualitative numerical measures of collection decay risks. We were able to accurately describe the indoor climate conditions of the analyzed building thanks to the data we collected. The assessment's main conclusions were that the May–July period represented the period with the highest degradation risk for all types of cultural assets (wood, leather, photos, and paintings); this occurred due to a combination of high amounts of water vapor and high air temperature conditions. The museum's structural and functional parameters, as well as the operating levels of the heating and air conditioning systems, the arrangement, load, and typological complexity of the artifacts displayed, were all taken into account. We were able to develop useful recommendations based on the results to stabilize the climate conditions inside the museum. Specific mitigation measures for the negative effects of the analyzed environmental factors are proposed. The results show that favorable conditions for mycelium growth occurred in the basement. The physicochemical factors that characterize the museum microclimate have an impact on cultural artifacts. To describe the environmental space and explain the type of deterioration of cultural artifacts, indices that analyze the environment for the preservation of cultural goods in museums were calculated in this study. The study provided a climate-induced risk assessment for the preservation of cultural artifacts in the "Poni-Cernatescu" Museum based on chemical, biological, and mechanical risks. Due to high relative humidity values, it was discovered that the climate conditions in the Basement were conducive to mold development during the summer months.