Influence of meteorological variables on PM2.5 concentrations in cities heated with solid fuels: A case study from Temuco, Chile

Abstract

Understanding how meteorological conditions influence fine particulate matter (PM_2.5) is crucial in cities where residential biomass combustion is a dominant emission source. This study analyses the effects of temperature, wind speed, relative humidity, atmospheric pressure and precipitation on PM_2.5 concentrations during the 2019 winter heating season in Temuco, Chile — a city largely dependent on wood for space heating. Data from 11 monitoring stations reveal that PM_2.5 levels increase with low temperatures and wind speeds, showing inverse correlations with both, temperature (r = −0.36 to −0.09) and wind speed (r = −0.30 to −0.24). Atmospheric pressure displays a weak positive correlation (r = 0.03–0.30), while humidity and precipitation show variable, site-specific effects. Extreme pollution episodes with PM_2.5 >500 μg/m³ coincide with periods of meteorological stability and an increased need for space heating. These results demonstrate that high PM_2.5 concentrations arise from the combined effect of strong local emissions and meteorological conditions that inhibit dispersion. The findings provide quantitative evidence to support weather-based air quality forecasting and targeted emission reduction strategies for biomass-dependent urban areas.