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Alcorcón is strategically situated in the southwest of the Community of Madrid, serving as a pivotal node within the metropolitan area's dense urban fabric. The city occupies a relatively flat plateau within the Tagus river basin, characterized by an undulating landscape that transitions from the urban sprawl of the capital toward the more open plains of the Castilian plateau. Its regional position is defined by its role as a commuter hub, tightly integrated with the M-50 and A-5 transport corridors, which facilitate massive daily vehicular flows. This proximity to high-capacity roads is a primary driver of its atmospheric profile, as nitrogen dioxide from combustion engines often lingers over the residential blocks. While the city lacks major bodies of water, its climate is heavily influenced by the distant Sierra de Guadarrama to the north, which can obstruct airflow and contribute to the stagnation of pollutants. The urban character is a blend of high-density residential neighborhoods and expansive industrial belts, particularly the Polígono Industrial, which introduces a localized mix of particulate matter and chemical emissions. This urban-rural gradient is sharp, with the edges of the city meeting agricultural fringes that provide some carbon sequestration but are often subjected to the drift of urban smog. Consequently, the terrain’s lack of significant vertical relief means that air quality is dictated less by topography and more by the interplay between anthropogenic emissions and the regional meteorological patterns typical of central Spain's interior.

Alcorcón’s air quality follows a distinct Mediterranean-Continental cycle, where meteorological shifts dictate pollutant concentrations. During winter, the city frequently experiences thermal inversions, a phenomenon where a layer of warm air traps cooler, polluted air near the ground. This leads to peaks in nitrogen dioxide and fine particulate matter, particularly during cold, windless mornings in December and January. Consequently, sensitive groups, such as asthmatics, should limit strenuous outdoor activity during these stagnant periods. Spring brings a transition; increasing wind speeds generally improve dispersion, although the season is marked by high pollen counts that exacerbate respiratory distress. Summer presents a different challenge: intense solar radiation and high temperatures trigger photochemical reactions, transforming precursors from traffic and industry into ground-level ozone. These ozone peaks typically occur in July and August, making mid-afternoon outings risky for children and the elderly. Autumn serves as a period of atmospheric cleansing, as the arrival of the first Atlantic fronts and rainfall facilitates wet deposition, scrubbing the air of accumulated particles. However, as temperatures drop in November, the stability of the atmosphere returns, signaling the onset of the winter stagnation cycle. To maintain respiratory health, residents are encouraged to monitor local alerts and favor early morning exercise during the summer or avoid peak traffic hours during the winter, ensuring that the timing of outdoor exposure aligns with the lowest predicted pollutant levels across the seasons.