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Qujing, situated in eastern Yunnan Province at coordinates 25.4910°N, 103.7960°E, occupies a strategic position in China's southwestern highlands, serving as a crucial transportation hub connecting Yunnan to Guizhou and Guangxi provinces. Nestled within the Yunnan-Guizhou Plateau at an average elevation of approximately 1,900 meters above sea level, the city's terrain is characterized by karst landscapes, rolling hills, and river valleys, with the Nanpan River flowing through its urban core. This elevated basin location creates a semi-enclosed topography that can trap air pollutants, particularly during temperature inversions common in plateau regions. Qujing functions as an important industrial and agricultural center within Yunnan, with its urban areas transitioning into extensive agricultural zones producing tobacco, grains, and vegetables. The city lies approximately 130 kilometers northeast of Kunming, placing it within Yunnan's eastern economic corridor where industrial activities including coal mining, chemical production, and manufacturing contribute to urban air pollution. While not directly coastal, Qujing's position inland means it lacks the moderating influence of large water bodies on air quality, though local rivers provide some moisture. The urban-rural gradient shows concentrated pollution sources in central districts gradually diminishing toward surrounding rural areas where agricultural burning occasionally occurs. This geographic configuration—a plateau basin with industrial activity—creates conditions where pollutants can accumulate, especially during stable atmospheric conditions typical of the region's climate.

Qujing's air quality follows distinct seasonal patterns influenced by the East Asian monsoon system and plateau meteorology. During winter (December-February), cold, stable atmospheric conditions frequently create temperature inversions that trap pollutants near the surface, particularly in the basin topography. These months often see the highest pollution levels as heating demands increase emissions and reduced vertical mixing allows fine particulate matter to accumulate. Sensitive groups should limit prolonged outdoor exposure during winter mornings when inversions are strongest. Spring (March-May) brings transitional weather with increasing temperatures and occasional dust from surrounding drylands, though rising convection helps disperse pollutants. The pre-monsoon period in late spring can experience occasional haze. Summer (June-August) offers the cleanest air as the southwest monsoon delivers abundant rainfall that effectively scavenges pollutants from the atmosphere, while increased vertical mixing further improves dispersion. This is the optimal season for outdoor activities. Autumn (September-November) begins with relatively good air quality that gradually deteriorates as monsoon rains retreat and atmospheric stability increases. The transition to winter conditions in late autumn sees rising pollution levels, particularly during calm, clear nights when radiation inversions form. Throughout the year, local fog—common in plateau basins—can interact with pollutants to create haze episodes, especially during cooler months. Wind patterns vary seasonally but generally remain light to moderate, with stronger winds during monsoon months providing better ventilation.