Chimá, nestled within the department of Córdoba, Colombia, occupies a strategically important position in the Magdalena River Valley. Located at approximately 9.15° latitude and -75.63° longitude, the town sits at an elevation of roughly 120 meters (394 feet) above sea level, placing it within a relatively flat, alluvial plain. This low-lying terrain, characteristic of the valley floor, is directly influenced by the Magdalena River, Colombia’s longest river, which flows nearby. The surrounding landscape is a mosaic of agricultural lands – primarily sugarcane and banana plantations – interspersed with patches of tropical dry forest. This agricultural intensity contributes to localized air quality concerns, particularly from burning practices during land clearing and harvesting. Chimá’s urban character is that of a small, developing municipality, with a predominantly rural hinterland. The urban–rural gradient is gradual, with agricultural activities seamlessly blending into the town’s periphery. The proximity to the Magdalena River, while providing a vital water source, can also exacerbate air quality issues during periods of drought, as reduced river flow concentrates pollutants. The region’s climate is hot and humid, typical of the Colombian Caribbean, with a distinct dry season. The lack of significant topographic barriers around Chimá allows for the relatively unimpeded movement of air masses, which can both disperse and concentrate pollutants depending on prevailing wind patterns and atmospheric stability. Industrial activity is limited, but the prevalence of agricultural processing facilities introduces localized emissions.

Chimá’s air quality experiences a pronounced seasonal cycle dictated by its tropical climate. The dry season, typically spanning December to April, presents the most significant air quality challenges. During these months, reduced rainfall and lower humidity contribute to the formation of temperature inversions, particularly in the early morning hours. These inversions trap pollutants close to the ground, leading to increased concentrations of particulate matter and other emissions from agricultural burning. The prevailing winds during this period are often light and variable, further hindering pollutant dispersion. Conversely, the wet season, from May to November, brings frequent rainfall and higher humidity, naturally cleansing the atmosphere and significantly improving air quality. The increased rainfall effectively ‘washes’ pollutants from the air, and higher wind speeds associated with occasional tropical storms help to disperse any remaining emissions. Months like March and April, coinciding with peak sugarcane harvesting, often see the worst air quality due to widespread burning. Sensitive groups, including children, the elderly, and individuals with respiratory conditions, should exercise caution during the dry season, limiting outdoor activities during peak pollution hours (early morning and late afternoon). During the wet season, while generally cleaner, periods of dense fog can temporarily reduce visibility and trap moisture-related pollutants. Maintaining indoor air quality through proper ventilation and air filtration is always advisable, particularly during periods of agricultural activity.