In this study, the outputs from Weather Research and Forecasting (WRF) regional climate model that has been dynamically downscaled the ECHAM5 Global Climate Model was used to investigate the regional climate change impact on air quality–related meteorological conditions in upper northern Thailand. The analyses were compared between the future (2045– 2064) and present (1990–2009) of the downscaled climate results. The meteorological variables that can potentially affect the regional air quality include temperature, planetary boundary layer height (PBLH), wind speed and ventilation index were analyzed during the majority air pollution season (haze season, January-April) in the study area. It was found that increase in Tmax can cause the increase of pollution sources while the increase in Tmin, causing the reduction of the vertical dispersion potential of pollutants, and yielding a favorable meteorological condition for pollutant accumulation. The surfaces wind and PBLH were predicted decreasing during air pollution season in the future, leading weaker ventilation rate in this region.
