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Nestled in the southeastern corner of the Korean Peninsula, Yangsan occupies a strategic position within the dynamic Gyeongnam region of South Korea. The city lies approximately 20 kilometers northwest of Busan, South Korea's second-largest metropolis and major port, placing it firmly within the Busan-Ulsan-Gyeongnam industrial corridor—one of the nation's most significant manufacturing and logistics hubs. Yangsan's terrain is characterized by the gentle slopes of the Nakdong River basin to the west and the foothills of the Yeongnam Alps to the north and east, creating a varied topography that influences local air circulation patterns. The city sits at a modest elevation averaging around 50 meters above sea level, with the Nakdong River flowing along its western periphery, providing some natural ventilation but also serving as a transportation corridor for industrial activities. This location places Yangsan in a transitional zone between the dense urban fabric of Busan and the more rural agricultural areas of inland Gyeongnam, creating an urban-rural gradient that affects pollution dispersion. The proximity to the East Sea (Sea of Japan) approximately 30 kilometers to the southeast offers some moderating maritime influence, while the surrounding mountains can occasionally trap pollutants during stable atmospheric conditions. The city's position within the industrial belt means it experiences both local emissions from transportation and residential sources, as well as regional pollution transported from the heavy industries of Ulsan and Busan, particularly when prevailing winds blow from the southwest.

Yangsan's air quality follows distinct seasonal patterns shaped by East Asian monsoonal circulation and local meteorological conditions. During winter (December-February), cold, dry continental air from the northwest often brings elevated particulate matter levels, particularly during temperature inversion episodes when cold air gets trapped beneath warmer layers, preventing pollutant dispersion. These inversions are most common in January and February, making these months particularly challenging for respiratory health. Spring (March-May) sees variable conditions—while increasing sunlight and warmer temperatures can help disperse pollutants, the region also experiences occasional yellow dust (hwangsa) events from the Gobi Desert, typically peaking in March and April, which can dramatically worsen air quality for days at a time. Summer (June-August) brings the East Asian monsoon with southerly winds from the Pacific, which generally improve air quality by dispersing local pollutants, though high humidity can occasionally lead to ozone formation on hot, sunny days. The cleanest air typically occurs during the late summer monsoon period. Autumn (September-November) begins with relatively good air quality but gradually deteriorates as temperatures drop and atmospheric stability increases, with October and November often seeing a buildup of pollutants before winter sets in. Sensitive groups including those with asthma, children, and the elderly should monitor air quality forecasts closely during winter inversion periods and spring dust events, limiting prolonged outdoor exertion during these times.