Global warming and the intensified urban heat island effect are degrading urban thermal environments, threatening residential living conditions and public health. As vital communities, educational campuses are also exposed to extreme heat, and those in hot-arid zones suffer most acutely. Enhancing campus outdoor thermal settings safeguards well-being, expands activity areas, boosts efficiency, and cuts energy use and carbon emissions. This research investigates the determinants that shape the outdoor environment of arid-region campuses and proposes optimization strategies. Multiple outdoor spaces with distinct functional roles on the Shihezi University campus were chosen for in situ monitoring of key thermal indicators. The work quantified how shading performance, building morphology, and surrounding vegetation influence summer thermal comfort and tested improvement scenarios through calibrated simulations. Results show that vegetation is the most effective regulator: tall trees can reduce air temperature by up to 4 degrees C and raise relative humidity by roughly 7 %, markedly elevating perceived comfort. Permeable paving consistently outperforms asphalt, concrete, and limestone under open-sky and shaded conditions. Building enclosure exerts only a modest influence, with semienclosed courtyards proving marginally preferable to fully enclosed forms. Additionally, the spatiotemporal pattern of campus microclimates is strongly governed by incoming solar radiation and prevailing wind direction: peak temperatures occur in vast open areas. At the same time, the highest humidity is observed within building shadows. These findings provide a scientific foundation for designing healthy, comfortable, resilient campus thermal environments in arid regions.