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Zhengjiatun, situated in the Songliao Plain of Jilin Province, occupies a strategic position in Northeast China's agricultural heartland. This mid-sized urban center lies approximately 200 kilometers northwest of Changchun, the provincial capital, placing it within the broader Northeast China Industrial Belt while maintaining strong connections to surrounding rural areas. The city's terrain is predominantly flat, with an elevation around 150 meters above sea level, characteristic of the Songnen Plain's gentle topography. This low-lying position creates natural drainage basins that can trap pollutants during stagnant atmospheric conditions. Zhengjiatun sits near the convergence of several river systems, including tributaries of the Liao River, though no major water bodies directly border the urban core. The surrounding landscape transitions from intensive agricultural zones—dominated by corn and soybean cultivation—to mixed urban-rural interfaces, creating a complex pollution gradient. Agricultural burning, particularly during harvest seasons, combines with urban emissions from transportation, residential heating, and small-scale industry to create a distinctive pollution profile. The city's location in China's northern grain belt means it experiences both urban and agricultural pollution sources, while its distance from major industrial centers like Shenyang moderates some industrial impacts. The flat terrain allows pollutants to disperse relatively easily under windy conditions but contributes to temperature inversions during calm periods, particularly in winter when cold air pools in the basin-like landscape.

Zhengjiatun's air quality follows a pronounced seasonal rhythm shaped by Northeast Asia's continental monsoon climate. Winter brings the most challenging conditions, typically from December through February, when temperature inversions trap pollutants close to the ground. Cold, stagnant air combines with increased emissions from coal-fired heating systems to create persistent haze episodes. Sensitive groups should limit outdoor activities during these months, particularly on calm, overcast days when dispersion is minimal. Spring offers gradual improvement as temperatures rise and winds increase, though March and April can see occasional dust storms from the Mongolian Plateau, mixed with lingering agricultural burning from field preparation. Summer provides the cleanest air, with June through August benefiting from southeasterly monsoon winds that disperse pollutants, frequent rainfall that scrubs the atmosphere, and reduced heating emissions. However, high humidity can occasionally combine with urban emissions to create ground-level ozone on hot, sunny days. Autumn begins with relatively good air quality in September but deteriorates in October and November as temperatures drop, heating systems activate, and agricultural burning peaks during the harvest season. The transition to winter heating creates a double burden of emissions during this period. For optimal outdoor activities, visitors should target late spring (May) or summer months, while residents with respiratory conditions should be particularly vigilant during heating seasons and harvest periods when multiple pollution sources converge.