Silchar, nestled in the Barak Valley of Assam in northeastern India, occupies a strategic position as the region's principal urban centre, situated on the banks of the Barak River. The city lies within the Cachar district, surrounded by lush tea gardens, rice paddies, and dense forests, creating a distinct urban–rural gradient where agricultural and domestic activities significantly influence local air quality. Silchar's terrain is predominantly flat to gently undulating, with an elevation of approximately 22 metres above sea level, which, combined with its humid subtropical climate, often traps pollutants near the ground. The city's location in a valley basin, flanked by the hills of Mizoram to the south and the Barail Range to the north, restricts wind circulation, exacerbating pollution accumulation, especially during cooler months. Proximity to the Barak River and numerous wetlands moderates humidity but also contributes to fog formation that can mix with emissions. While not part of a major industrial belt, Silchar's economy revolves around tea processing, small-scale manufacturing, and commerce, with pollution sources like brick kilns and construction dust prevalent on its outskirts. The urban fabric blends colonial-era architecture with modern developments, and as a transportation hub connecting Assam to Manipur and Mizoram, vehicle exhaust from congested roads is a persistent issue. This geographic setting, where urban emissions interact with rural biomass burning and natural topographic barriers, creates a complex air quality dynamic unique to this northeastern Indian city.

Silchar's air quality follows a pronounced seasonal rhythm shaped by its humid subtropical climate and monsoon patterns. During winter (November to February), pollution peaks dramatically due to a combination of meteorological and human factors. Cool temperatures and frequent temperature inversions trap pollutants close to the ground, while low wind speeds and dense fog—often exacerbated by moisture from the Barak River—create a stagnant atmosphere that accumulates emissions from vehicles, brick kilns, and widespread biomass burning for heating. These months are particularly hazardous for outdoor activity, with sensitive groups like children, the elderly, and those with respiratory conditions advised to limit exposure and use masks. Spring (March to May) sees gradual improvement as temperatures rise and winds increase, though pre-monsoon dust storms and ongoing construction can cause intermittent spikes. The monsoon season (June to September) brings the cleanest air, as heavy rainfall from the southwest monsoon scrubs pollutants from the atmosphere, with winds dispersing emissions—this is the optimal time for outdoor pursuits. Post-monsoon (October) marks a transition, with reducing rainfall and increasing biomass burning leading to deteriorating air quality ahead of the winter peak. Health guidance emphasises monitoring local air quality reports year-round, with winter requiring the most vigilance, including indoor air purifiers for vulnerable residents.