Influence of meteorology on atmospheric fine particulate matter (PM2.5) dispersion over Addis Ababa, Ethiopia

Meteorological drivers and PM2.5 pollution have a significant relation; however, in Addis Ababa city, there is a critical research gap, underscoring the need to understand seasonal and diurnal variability to develop effective air quality management strategies in rapidly urbanizing, high-altitude cities of the Global South. Thus, this study provides a comprehensive analysis of PM₂.₅ and associated meteorological variables in the city. The dataset, comprising hourly observations from January 2023 to December 2024, highlights key statistical summaries, spatial distributions, and temporal patterns of PM₂.₅ concentrations alongside Relative Humidity (RH), Wind Speed (WS), Wind Direction (WD), and Air Temperature (Tair). PM₂.₅ levels ranged from 1 µg/m3 to 293 µg/m3, with an average concentration of 34.21 µg/m3, exceeding the annual the WHO guideline limit. Increasing PM₂.₅ levels were observed during early mornings and late evenings, as well as in June to September, likely influenced by meteorological factors such as reduced WS, temperature inversions, and seasonal activities. Spatial interpolation analysis revealed hotspots of PM₂.₅ in the western and southern districts, which may relating with commercial activities, industrial activities and traffic emissions, while the northern areas exhibited lower concentrations due to green spaces and favorable dispersion conditions. WD analysis identified higher PM₂.₅ levels originating from the east and southeast, pointing to potential pollution sources in those directions. Temporal trends indicated an inverse relationship between PM₂.₅ concentrations and wind speeds, while higher temperatures during warmer months correlated with increased PM₂.₅ levels, suggesting enhanced photochemical activity. This study emphasizes the need for targeted mitigation strategies to address spatial and temporal variability in PM₂.₅ pollution and its contributing factors. These findings provide valuable insights for air quality management and policy development in urban environments.