Idar is a historic city nestled in the Sabarkantha district of Gujarat, India, situated at coordinates 23.8390°N, 73.0020°E. Located in the western part of the country, it lies approximately 100 kilometers northeast of Ahmedabad, Gujarat's largest city and industrial hub, placing it within the broader economic and pollution influence of the Ahmedabad-Vadodara industrial corridor. The city sits at an elevation of around 150 meters above sea level on the fringes of the Aravalli Range, a low mountain chain that runs through Rajasthan and Gujarat, providing some topographic variation but not significant enough to create major air drainage patterns. Idar is characterized by a semi-arid landscape, with the Sabarmati River basin to the south and west, though the city itself is not directly adjacent to large water bodies, reducing any moderating effects on local climate and pollution dispersion. The urban area blends with surrounding agricultural zones, primarily dedicated to cotton, groundnut, and wheat cultivation, which contribute to seasonal biomass burning and dust. Idar's position in a transitional zone between urban-industrial Gujarat and rural hinterlands means it experiences a mix of pollution sources: local vehicular emissions, small-scale industries, construction dust, and agricultural residue burning. The flat to gently rolling terrain, combined with its inland location away from coastal breezes, often leads to stagnant air conditions, particularly in winter, trapping pollutants and exacerbating air quality issues. This geographic setting makes Idar vulnerable to accumulating both locally generated and regionally transported pollutants, especially during periods of low wind speeds.

In Idar, air quality follows a distinct seasonal pattern influenced by the region's semi-arid climate and monsoon cycle. During winter (November to February), pollution peaks due to meteorological factors: cold temperatures lead to frequent temperature inversions that trap pollutants near the ground, while calm winds from the northeast fail to disperse emissions. This season sees heightened levels of particulate matter from vehicular exhaust, industrial activities, and biomass burning for heating, making it the worst time for outdoor activities, especially for sensitive groups like children, the elderly, and those with respiratory conditions, who should limit exposure and use masks. Spring (March to May) brings rising temperatures and occasional dust storms from the Thar Desert to the northwest, increasing coarse particulate matter, though stronger daytime winds provide some ventilation; outdoor exercise is best done in early mornings before pollution builds up. The monsoon (June to September) offers relief as heavy rainfall from the southwest monsoon washes pollutants from the air, leading to the cleanest air of the year—ideal for outdoor pursuits, though high humidity can aggravate asthma. Post-monsoon (October) sees a gradual deterioration as rainfall ceases, agricultural burning resumes, and winds weaken, setting the stage for winter peaks. Throughout the year, fog is rare, but haze from pollution and dust can reduce visibility, particularly in dry months. Sensitive individuals should monitor local air quality reports and plan activities accordingly, favoring the monsoon period for minimal health risks.