Guéné, nestled within the Atacora Department of Benin, occupies a geographically significant position in the country’s northwest. Located at coordinates 11.7306, 3.2242, the city is characterized by undulating terrain typical of the Atacora Mountains, a region known for its peninsular formations and rocky outcrops. The elevation, while not extreme, contributes to localized microclimates influencing air dispersion. Guéné isn’t directly adjacent to a major body of water, though smaller rivers and streams dissect the surrounding landscape, providing crucial irrigation for the predominantly agricultural lands. The urban character of Guéné is defined by a strong urban-rural gradient; the city centre is relatively compact, transitioning quickly into farmland and savannah grasslands. This proximity to agricultural zones introduces potential sources of particulate matter from land preparation, harvesting, and the burning of agricultural residue. While Guéné isn’t a major industrial hub, small-scale processing of agricultural products and local craft industries contribute to localized emissions. Dust from unpaved roads is a significant factor, particularly during the dry season. The surrounding landscape, largely savannah and woodland, limits natural air filtration, making the city more susceptible to regional dust transport from the Sahara. The prevailing winds, influenced by the Harmattan, further exacerbate this effect.

Guéné experiences a distinct wet and dry season, profoundly impacting air quality. The dry season, roughly November to April, witnesses the poorest air quality. Reduced rainfall means dust and particulate matter remain suspended for longer, exacerbated by Harmattan winds blowing from the Sahara. Agricultural burning, common during land preparation for the next planting season, adds significantly to particulate pollution. Temperature inversions, more frequent during cooler nights within the dry season, trap pollutants near ground level. May marks the transition, with increasing rainfall beginning to cleanse the air. The wet season, June to October, generally offers the best air quality. Frequent rainfall effectively washes away pollutants, and higher humidity reduces dust resuspension. However, even during the wet season, localized pollution from vehicle emissions and small-scale industries persists. September and October, towards the end of the rainy season, can see a slight increase in humidity-related mould spores, potentially affecting respiratory health. Sensitive groups – children, the elderly, and those with pre-existing respiratory conditions – should limit strenuous outdoor activity during the peak of the dry season (December-February) and be mindful of potential mould exposure towards the end of the wet season. Monitoring local conditions is crucial.