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Dhaka, the capital of Bangladesh, occupies a strategic position in South Asia, situated on the northern banks of the Buriganga River within the vast Ganges-Brahmaputra delta. This megacity lies at approximately 23.7°N latitude and 90.4°E longitude, with an average elevation of just 4 meters above sea level, making it exceptionally flat and prone to flooding. The urban landscape is densely packed, characterized by rapid, unplanned expansion that merges into surrounding agricultural zones and industrial belts, particularly to the north and west where textile factories and brick kilns cluster. Dhaka's location in a riverine basin surrounded by low-lying floodplains and wetlands traps pollutants, as the terrain lacks natural ventilation corridors. Proximity to the Bay of Bengal, about 200 kilometers to the south, influences humidity but does little to disperse airborne contaminants due to weak prevailing winds. The city's urban–rural gradient is stark, with core areas exhibiting extreme population density that exacerbates emissions from vehicles, construction, and domestic sources, while peripheral regions blend into rice paddies and seasonal crop fields that contribute agricultural burning residues. This geographic setting, combined with its position in one of the world's most populous river deltas, creates a perfect storm for poor air quality, where topographical and meteorological conditions frequently conspire to concentrate pollutants over the metropolitan area.

Dhaka's air quality follows a distinct seasonal pattern driven by the South Asian monsoon and local meteorological conditions. In winter (December to February), pollution peaks dramatically due to temperature inversions that trap pollutants close to the ground, combined with low wind speeds and frequent fog, making these months particularly hazardous for outdoor activities; sensitive groups like children, the elderly, and those with respiratory conditions should limit exposure. Spring (March to May) sees a gradual improvement as temperatures rise and winds increase, though pre-monsoon dust storms and lingering industrial emissions can still cause moderate pollution levels. The summer monsoon (June to September) brings the cleanest air, as heavy rainfall scrubs pollutants from the atmosphere and strong southwesterly winds disperse contaminants, offering the best time for outdoor pursuits. Autumn (October to November) marks a transition back to worsening conditions, with decreasing rainfall and the onset of cooler temperatures that again foster pollutant accumulation. Throughout the year, health guidance emphasizes monitoring local air quality reports, using masks during peak pollution periods, and planning activities for early mornings or late evenings when pollution levels may be lower, especially in winter when inversions are most persistent.