Araria is situated in the northeastern corner of Bihar, India, positioned at coordinates 26.1500°N, 87.5100°E within the humid subtropical climate zone. This city lies in the fertile plains of the Mithila region, approximately 50 kilometers south of the Nepal border, placing it within a transboundary airshed that influences pollution patterns. The terrain is predominantly flat alluvial plains with an elevation of around 47 meters above sea level, lacking natural topographic barriers that might disperse pollutants. Araria is surrounded by intensive agricultural zones, particularly rice paddies and wheat fields, which contribute to seasonal burning practices. The city sits near several rivers, including the Kosi River to the west, known as 'the sorrow of Bihar' for its frequent flooding, but these water bodies do little to mitigate air pollution due to the region's stagnant atmospheric conditions. Urban development follows a linear pattern along major roads, with a distinct urban-rural gradient where the city center transitions rapidly to farmland. This geography creates a perfect storm for poor air quality: the flat terrain prevents wind dispersion, agricultural burning adds particulate matter, and the city's position in the Indo-Gangetic Plain—a notorious pollution hotspot—means it receives transported pollutants from neighboring regions. Domestic biomass burning for cooking and heating is prevalent due to limited clean energy access, while brick kilns operate seasonally, adding industrial emissions to the mix.

Araria's air quality follows a dramatic seasonal cycle shaped by its humid subtropical climate and agricultural calendar. During winter (November to February), pollution peaks severely due to multiple converging factors: agricultural crop burning after the kharif harvest, increased domestic biomass burning for heating, and meteorological conditions like temperature inversions that trap pollutants near the ground. Dense fog frequently forms, combining with particulate matter to create hazardous smog that reduces visibility and exacerbates respiratory issues. Cold waves further intensify heating needs, worsening emissions. Sensitive groups—children, elderly, and those with pre-existing conditions—should avoid outdoor activities entirely during these months and use air purifiers indoors. Spring (March to May) brings some relief as temperatures rise and winds increase, dispersing pollutants moderately, though extreme heat can cause ground-level ozone formation. The monsoon season (June to September) offers the cleanest air as heavy rains wash pollutants from the atmosphere and winds from the Bay of Bengal sweep through the region. This is the optimal time for outdoor activities. Post-monsoon (October) sees a rapid deterioration as farmers prepare fields through burning, heralding the return of hazardous conditions. Year-round, vehicle exhaust and open waste burning contribute a baseline of pollution, but seasonal agricultural and domestic practices drive the extreme peaks.