Ozone (O₃) pollution is one of the predominant environmental problems, and exposure to high O₃ concentrations has a significant negative influence on both human health and ecosystems. Therefore, it is essential to analyze spatio-temporal characteristics of O₃ distribution and to evaluate O₃ exposure levels. In this study, O₃ monitoring and satellite data were used to estimate O₃ daily, seasonal and one-year exposure levels based on the Bayesian maximum entropy (BME) model with a spatial resolution of 1 km × 1 km in the Beijing-Tianjin-Hebei (BTH) region, China. Leave-one-out cross-validation (LOOCV) results showed that R² for daily and one-year exposure levels were 0.81 and 0.69, respectively, and the corresponding values for RMSE were 19.58 μg/m³ and 4.40 μg/m³, respectively. The simulation results showed that the heavily polluted areas included Tianjin, Cangzhou, Hengshui, Xingtai, and Handan, while the clean areas were mainly located in Chengde, Qinhuangdao, Baoding, and Zhangjiakou. O₃ pollution in summer was the most severe with an average concentration of 134.5 μg/m³. In summer, O₃ concentrations in 87.7% of the grids were more than 100 μg/m³. In contrast, winter was the cleanest season in the BTH region, with an average concentration of 51.1 μg/m³.

In recent years, ozone (O₃) concentration has shown a decreasing trend in the Beijing–Tianjin–Hebei (BTH) region in China. However, O₃ pollution remains a prominent problem. Accurate estimation of O₃ exposure levels can provide support for epidemiological studies. A total of 13 variables were combined to estimate short- and long-term O₃ exposure levels using the geographically weighted regression (GWR) model in the BTH region with a spatial resolution of 1 × 1 km from 2017 to 2020. Five variables were left in the GWR model. O₃ concentration was positively correlated with temperature, wind speed, and SO₂, whereas is was negatively correlated with precipitation and NO₂. Results showed that the model performed well. Leave-one-out cross-validation (LOOCV) R² for short- and long-term simulation results were 0.91 and 0.71, and the values for RMSE were 11.14 and 3.49 μg/m³, respectively. The annual maximum 8 h average O₃ concentration was the highest in 2018 and the lowest in 2020. Decreasing concentrations of major precursors of O₃ due to the regional joint prevention and control may be the reason. O₃ concentration was high in the southeast of the BTH region, including in Hengshui, Handan, Xingtai and Cangzhou.