Hubli, situated in the northwestern part of Karnataka at coordinates 15.3502°N, 75.1376°E, occupies a strategic position in India's Deccan Plateau region. The city lies at an elevation of approximately 670 meters above sea level, which provides some natural ventilation but also creates conditions for temperature inversions that can trap pollutants. Hubli's urban character is defined by its role as a major commercial and industrial hub in North Karnataka, with a population nearing one million creating significant urban density. The city's geography places it within the Malnad region transition zone, surrounded by gently rolling terrain with scattered hills to the west and agricultural plains extending eastward. This location creates an urban-rural gradient where pollution from the city can affect surrounding farmlands, while agricultural burning occasionally impacts urban air quality. Hubli's proximity to the Tungabhadra River basin, approximately 20 kilometers to the northeast, provides some moisture but insufficient to significantly mitigate pollution. The city sits within an emerging industrial belt connecting to neighboring Dharwad, with manufacturing, textile processing, and transportation sectors contributing to particulate emissions. The regional position as a transportation crossroads for highways and railways connecting Mumbai, Bangalore, and Goa means heavy vehicular traffic compounds local emissions. The surrounding landscape of mixed agriculture—primarily sugarcane, cotton, and pulses—means seasonal crop residue burning can influence air quality, particularly during post-harvest periods. The city's elevation on the plateau creates a basin-like effect where pollutants can accumulate during calm weather conditions, while the distance from major water bodies limits the cleansing effect of sea breezes that coastal cities experience.

Hubli's air quality follows a distinct seasonal pattern shaped by the region's tropical savanna climate with pronounced monsoon influence. During winter (December-February), cool temperatures and frequent temperature inversions trap pollutants close to the ground, creating the year's worst air quality conditions. Morning fog combines with vehicle emissions and biomass burning to form persistent haze, making these months particularly challenging for respiratory patients who should limit outdoor activities, especially during early mornings. Spring (March-May) brings rising temperatures and increasing wind speeds that help disperse pollutants, though occasional dust storms from surrounding drylands can temporarily degrade air quality. The pre-monsoon heat creates convection currents that lift pollutants higher into the atmosphere, providing some relief at ground level. Summer (June-August) coincides with the southwest monsoon, bringing heavy rainfall that effectively scrubs the air of particulate matter, resulting in the cleanest air of the year. The monsoon winds from the Arabian Sea provide excellent ventilation, making this the optimal season for outdoor activities for all population groups. Autumn (September-November) sees diminishing rains and the return of stagnant atmospheric conditions. Post-monsoon agricultural burning in surrounding farmlands, combined with reduced wind speeds and the onset of cooler temperatures, creates a gradual deterioration in air quality through November. Sensitive groups including children, elderly, and those with pre-existing respiratory conditions should be particularly cautious during the winter inversion periods and the post-monsoon transition when pollutant concentrations increase rapidly.