Upper northern Thailand faced a crisis of air pollution, posing significant challenges to respiratory health. This study aimed to investigate the trends and associations between air pollutant levels and lung cancer and chronic obstructive pulmonary disease (COPD). This study spanned eight provinces over 2013–2022, collecting air pollutant monitoring data from the Pollution Control Department and respiratory health information, including mortality rates for lung cancer and COPD patients, along with the readmission rate for COPD patients, from Regional Public Health. The dataset was divided into two seasons, namely, the haze (December-May) and non-haze (June-November) seasons. The findings indicated a decadal pattern, with peak levels observed in March for all air pollutant parameters and COPD readmission rates. The PM2.5 concentration exceeded Thailand's air quality standards from January to April. COPD mortality and readmission rates significantly increased compared to those in the non-haze periods (p < 0.001). While lung cancer mortality rates were greater in the haze season, the difference was not statistically significant. Pearson correlation analysis indicated moderate positive associations between PM10, PM2.5, O3, CO, and NO2 levels and COPD readmission rates (r = 0.308 to 0.495, p < 0.01). Moreover, the PM10, PM2.5, O3, SO2 and NO2 concentrations exhibited a weak positive association with the COPD mortality rate (r 0.014 to 0.288, p < 0.01). Upper northern Thailand experienced a predictable pattern of air pollution, positively linked to higher COPD death and readmission rates. These findings highlight the need for an early and well-prepared public health response, especially before the haze season.