Abstract: In the context of climate warming and urban expansion, this study aims to understand the urban heat island (UHI) changes in Chengdu City over the past decade. To this end, this study, based on inverted surface temperature and multi-source data from moderate-resolution imaging spectroradiometer (MODIS) data between 2014 and 2023, analyzed the spatiotemporal variations in interannual and seasonal UHI in Chengdu and conducted a comparative analysis using the mean standard deviation method, linear trend analysis, and correlation analysis. It further conducted correlation and comparative analyses of the UHI influencing factors. The results indicate that the daytime UHI showed a downward trend over time in spring and winter, but an upward trend in summer, autumn, and at the interannual scale. In contrast, the nighttime UHI in spring and at the interannual scale decreased over time, but increased in summer, autumn, and winter. Comparison analysis indicates that the summer exhibited significantly lower UHI than the other three seasons. The temporal variations in the proportion of UHI area followed a similar trend in spring, summer, and autumn, but an opposite trend in winter and at the interannual scale. In terms of the spatial distribution, the daytime UHI generally increased from southwest to northeast, while the nighttime UHI fluctuated in the same direction. Comparison analysis reveals that daytime exhibited a more concentrated UHI distribution compared to nighttime. Specifically, the daytime UHI formed a clustered distribution pattern around the city center, whereas the nighttime UHI presented a more fragmented pattern. In addition, the primary factors influencing the proportion of UHI area were identified as DEM and the number of foggy days during the daytime, and DEM, precipitation, relative humidity, PM_2.5 concentration, and green coverage rate in the built- up urban area during nighttime. The results provide important reference for the rational layout of future urban planning and construction and the improvement of the urban thermal environment in Chengdu City.