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Alfenas is strategically positioned in the southern region of Minas Gerais, nestled within a landscape characterized by the rolling hills and undulating plateaus typical of the Mantiqueira foothills. This urban center serves as a vital regional hub, blending its educational identity as a university town with a deeply rooted agrarian economy. The terrain is marked by significant elevation changes, which create a complex microclimate that directly influences the dispersion of atmospheric pollutants. To the east and south, the vast expanse of the Furnas Lake provides a moderating influence on local temperatures and humidity, often introducing moist air masses that can scrub particulate matter from the lower atmosphere. However, the city is surrounded by an intensive agricultural belt, dominated by coffee plantations and livestock grazing, creating a distinct urban–rural gradient. This proximity to farmland means that the air quality is frequently influenced by seasonal biomass burning and the use of agrochemicals, which can drift into the urban core. The city's layout, interspersed with green corridors and steep slopes, creates pockets where air can stagnate, particularly in the valley floors during periods of low wind speed. Consequently, the geographic positioning of Alfenas makes it susceptible to the accumulation of pollutants from both vehicular traffic and regional agricultural practices, balancing the freshness of the highland air with the challenges of localized anthropogenic emissions and the natural topography of the Minas Gerais interior. This unique spatial arrangement ensures that air quality fluctuates based on wind direction and seasonal land-use patterns across the southern Minas landscape.

In Alfenas, air quality follows a binary tropical rhythm divided into the wet and dry seasons. During the summer months, from October to March, heavy precipitation and frequent thunderstorms provide a natural cleansing mechanism, washing particulates and aerosols from the sky. This period offers the cleanest air, making it ideal for outdoor activities and respiratory health. However, as the region transitions into the dry winter season, typically from May to September, the meteorological profile shifts dramatically. The lack of rainfall, combined with the prevalence of atmospheric temperature inversions, traps pollutants closer to the ground. During these colder months, the air becomes stagnant, and the incidence of biomass burning—used for land preparation in the surrounding coffee and sugarcane fields—peaks. This leads to a noticeable increase in fine particulate matter, often manifesting as a hazy veil over the city. August and September are particularly critical, as the lowest humidity levels exacerbate the suspension of dust and smoke. Sensitive groups, including children, the elderly, and those with chronic asthma, should limit prolonged outdoor exertion during the early morning hours when inversions are strongest. Conversely, the transition periods of spring and autumn offer moderate conditions, though the arrival of the first rains in October remains the most anticipated event for air purification. By understanding this cycle, residents can better manage their health exposure, favoring the humid summer months for high-intensity exercise and cautioning against the dry winter haze that characterizes the southern Minas interior during the year's coldest stretch.