The study analyzed the urban heat island effect in Xining City, China, from 1996 to 2011. By using satellite images and meteorological data, researchers found that the city experienced a significant urban heat island effect, with the heat island area expanding over time. The strongest heat island effect was observed in winter, decreasing in summer and autumn. The study also revealed that the land surface temperature was negatively correlated with greenery (NDVI) and positively correlated with built-up areas (NDBI). The findings suggest that urban sprawl contributes to the urban heat island effect, and strategies to mitigate this effect are needed to improve the city's thermal environment in the future.