Yufu Air Quality Index (AQI)

Loading live AQI data...

Loading historical AQI trends...

Yufu, nestled in the heart of Ōita Prefecture on the island of Kyushu, Japan, presents a unique geographic setting influencing its air quality. The city sits within a broad, gently sloping basin, surrounded by the Yufu Mountains, a range formed by volcanic activity. This terrain, reaching elevations of over 1,000 meters, creates a natural bowl effect, potentially trapping air pollutants during periods of atmospheric stability. The Yufu River, a key waterway, flows through the city, offering some natural ventilation but also contributing to humidity which can affect pollutant dispersion. Yufu is not a heavily industrialised city; its economy is largely driven by tourism, particularly its renowned hot springs (onsen), and agriculture, primarily rice cultivation in the surrounding plains. The urban-rural gradient is relatively sharp, with dense residential areas concentrated around the train station and gradually transitioning to agricultural land and forested slopes. Proximity to the Beppu Bay coastline, approximately 30km west, introduces maritime influences, but the mountainous barrier limits direct coastal airflow. The basin’s topography, combined with seasonal weather patterns, dictates the city’s air quality dynamics, making it susceptible to localised pollution events despite its overall rural character. Understanding these geographical factors is crucial for effective air quality management in Yufu.

Yufu’s air quality follows a distinct seasonal pattern. Spring (March-May) often sees increased particulate matter from agricultural burning as farmers prepare fields for rice planting, coupled with pollen from local cedar trees, impacting respiratory health. Summer (June-August) brings the humid subtropical climate and occasional typhoons. While rainfall generally washes away pollutants, stagnant air during typhoon breaks can lead to localised build-up. Autumn (September-November) is typically the clearest period, benefiting from cooler temperatures and prevailing northerly winds that flush out accumulated pollutants. However, temperature inversions can occur, trapping cool air and pollutants in the basin. Winter (December-February) presents the most challenging conditions. Reduced sunlight hours and stable, cold air masses exacerbate pollution, particularly from residential heating sources like wood stoves. Fog is also common, increasing particulate matter concentration. Sensitive groups – children, the elderly, and those with respiratory conditions – should limit strenuous outdoor activity during winter mornings and periods of fog. Springtime pollen sufferers should monitor forecasts and take preventative measures. Overall, avoiding outdoor exertion during calm, cold winter days and peak agricultural burning in spring is advisable for maintaining respiratory health.