The study aims to monitor PM2.5 concentrations in the north-eastern and eastern regions of Thailand for the past 5 years (from 2017 to 2021) from satellite observations for monitoring air quality. To ensure the PM2.5 concentrations from satellite data of NASA’s MEERA2 products, it is necessary to evaluate and analyze the relationship between PM2.5 data from satellite observations and higher precision data from ground-based stations of the Pollution Control Department (PCD) in terms of various statistical values, such as squared correlation coefficient (R2), mean (Bias) and Root Mean Square Error (RMSE). Then, the estimation of the monthly average for PM2.5 concentrations was performed using satellite data of MERRA2 products by bias correction method with twenty PCD’s ground stations. The result shows that before correcting the relationship value is relatively low, the performance of estimating PM2.5 concentrations from satellite data needs to be improved from the monthly average using the bias correction method. After bias-corrected, a correlation coefficient (R2) value of 0.73 was improved from 0.56. A mean (Bias) of 0.03 µg/m3 and an RMSE of 6.39 µg/m3 were decreased. It is clear that bias correction can help to improve estimating PM2.5 concentrations from MEERA2 products.