San Francisco Air Quality Index (AQI)

Loading live AQI data...

Loading historical AQI trends...

San Francisco, Agusan del Sur, nestled within the heart of Mindanao in the Philippines, presents a unique geographic context influencing its air quality. The city sits at approximately 8.5100°N latitude and 125.9800°E longitude, characterized by a generally flat to gently rolling terrain. This area forms part of the Agusan River Basin, a vast floodplain dominated by the Agusan River, the third-longest river in the Philippines. The surrounding landscape is predominantly agricultural, with significant rice paddies, banana plantations, and coconut groves. While not heavily industrialized *within* San Francisco itself, the broader Agusan del Sur province experiences some logging and small-scale mining activities upstream, potentially contributing to sediment and pollutant runoff. The urban-rural gradient is relatively sharp; the city centre quickly transitions to agricultural land. This proximity to agricultural practices introduces potential sources of particulate matter from field preparation, burning of agricultural waste, and pesticide/fertilizer application. The city’s elevation is relatively low, increasing susceptibility to humidity and temperature inversions, which can trap pollutants near the ground. The prevailing winds, influenced by the Philippine monsoon system, play a crucial role in dispersing or concentrating these pollutants. The river itself, while a vital resource, can also act as a conduit for pollutants during heavy rainfall events, impacting localized air quality.

San Francisco, Agusan del Sur, experiences a pronounced wet and dry season, dictating the patterns of air quality throughout the year. The dry season, typically from March to May, sees a peak in particulate matter pollution. This is largely due to increased agricultural burning to clear fields for the next planting season, coupled with drier conditions that allow dust and soil erosion to contribute to airborne particles. Lower humidity during these months also reduces the natural scavenging of pollutants by rainfall. The onset of the wet season, around June, brings a significant improvement in air quality as rainfall washes away pollutants and suppresses dust. However, increased humidity can also foster mold growth, potentially impacting indoor air quality. The peak of the wet season, July to September, often coincides with the strongest monsoon winds, which effectively disperse pollutants. October to November represents a transitional period, with decreasing rainfall and a gradual return to drier conditions. Sensitive groups – children, the elderly, and those with respiratory conditions – should be particularly cautious during the dry season, limiting strenuous outdoor activity. Fog, common during the cooler months, can exacerbate pollution by trapping pollutants near ground level. Monitoring wind direction during agricultural burning is crucial for avoiding exposure.