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Nestled in the fertile plains of Māzandarān Province in northern Iran, Qā’em Shahr occupies a strategic position approximately 20 kilometres south of the Caspian Sea coast, with the Alborz mountain range rising dramatically to its immediate south. This city of nearly 250,000 people sits at a modest elevation of around 50 metres above sea level, placing it within the Caspian Hyrcanian mixed forests ecoregion, one of Iran's most agriculturally productive zones. The urban character of Qā’em Shahr reflects its role as a regional administrative and commercial hub, with development patterns showing a clear urban–rural gradient as the city merges into surrounding rice paddies, citrus orchards, and tea plantations. Its location specifically affects air quality through several mechanisms: proximity to the Caspian Sea moderates temperatures but can contribute to humidity and fog formation that traps pollutants, while the towering Alborz mountains to the south create a natural barrier that limits atmospheric ventilation, particularly during periods of temperature inversion. The city lies within Iran's northern industrial belt, with manufacturing activities concentrated along transportation corridors, while agricultural burning in surrounding rural areas adds seasonal particulate matter. The Caspian coastal plain's flat terrain allows for urban sprawl and transportation networks that generate mobile emissions, yet the same topography lacks natural wind corridors that might otherwise disperse pollution efficiently.

In Qā’em Shahr, air quality follows a distinct seasonal pattern shaped by the Caspian region's unique meteorology. During winter (December-February), cold air drainage from the Alborz mountains creates frequent temperature inversions that trap pollutants close to the ground, compounded by residential heating emissions and reduced atmospheric mixing; these months typically see the poorest air quality, with sensitive groups advised to limit prolonged outdoor exposure. Spring (March-May) brings gradual improvement as increasing solar radiation breaks up inversions and Caspian sea breezes enhance dispersion, though agricultural burning in surrounding farmlands can cause episodic spikes in particulate matter. Summer (June-August) offers the cleanest air despite higher temperatures, as consistent northerly winds from the Caspian Sea ventilate the basin and convective mixing reaches maximum efficiency, making this the optimal season for outdoor activities. Autumn (September-November) marks a transitional period where declining temperatures and increasing humidity create conditions for radiation fog that can trap pollutants, particularly during calm mornings before daytime winds develop. Throughout the year, the city experiences minimal precipitation during summer months but receives adequate rainfall in other seasons to occasionally wash pollutants from the atmosphere. Sensitive individuals should monitor local air quality reports particularly during winter inversion episodes and autumn fog events, when particulate matter concentrations tend to peak.