Karur, situated in the central part of Tamil Nadu at coordinates 10.9601°N, 78.0766°E, lies within the fertile Cauvery River basin, approximately 130 meters above sea level on the Deccan Plateau. This inland city, positioned about 75 kilometers northwest of Tiruchirappalli, serves as a crucial textile and transport hub along National Highway 44, connecting major southern cities like Coimbatore and Madurai. Karur's urban character blends traditional weaving industries with modern bus body manufacturing, creating a distinct industrial-urban landscape surrounded by agricultural zones growing cotton, turmeric, and bananas. The city's location in the rain shadow region of the Western Ghats significantly impacts its air quality, as pollutants from local industries—particularly textile dyeing units and workshops—tend to accumulate in the relatively flat terrain with minimal natural ventilation. Proximity to the Amaravathi River, a tributary of the Cauvery, provides some moisture but insufficient to consistently disperse pollutants. The urban-rural gradient shows dense industrial clusters in the city center gradually transitioning to agricultural outskirts, creating a pollution plume that affects both urban and peri-urban areas. Karur's position within Tamil Nadu's industrial belt, combined with its tropical wet-and-dry climate, creates a geographical context where local emissions interact with regional weather patterns to produce persistent air quality challenges, especially during the dry winter months when atmospheric conditions favor pollutant stagnation.

Karur's air quality follows a distinct seasonal pattern shaped by its tropical wet-and-dry climate and local emission sources. During the winter months from November to February, pollution peaks dramatically due to multiple converging factors: lower temperatures create frequent temperature inversions that trap pollutants near the surface, while calm winds and morning fog further inhibit dispersion. This period coincides with increased biomass burning for heating and agricultural residue management, compounding emissions from perennial sources like textile dyeing and vehicular traffic. Sensitive groups, including children, elderly residents, and those with respiratory conditions, should minimize outdoor activities during these months, particularly in early mornings when pollution concentrations are highest. The summer season from March to May brings extreme heat that can elevate ground-level ozone formation, though stronger daytime winds and convective mixing provide some pollutant dispersal—making late afternoons relatively better for outdoor exertion. The southwest monsoon from June to September dramatically improves air quality as heavy rainfall scrubs pollutants from the atmosphere and consistent winds provide ventilation, creating the cleanest period of the year. The brief northeast monsoon in October offers transitional conditions before winter stagnation sets in again. For health protection, residents should monitor local air quality advisories, use air purifiers during peak pollution months, and schedule outdoor activities for monsoon periods when natural cleansing occurs most effectively.