This work summarizes and analyzes the climate state and air quality of Peninsular Malaysia based on selected ground-based observations of the temperature, precipitation, relative humidity, wind speed, wind direction and concentrations of PM10, O3, CO, NO2, and SO2 over the past 20 years (2000–2019). 

The observational data are obtained from observatories in Peninsular Malaysia, and they include the hourly temperature, relative humidity, wind speed, wind direction, the concentrations of particulate matter (PM10), ozone (O3), carbon monoxide (CO), nitrogen dioxide (NO2), and sulfur dioxide (SO2), and daily mean rainfall, resulting in a total of 10 variables, ranging from 01/01/2000 to 12/31/2019. The observation data used are shown in Appendix 1 (Data Source and Availability). The dataset is averaged to obtain the annual mean for illustration. Due to the different instruments and contractors of the air quality stations, the data after 2017 is calibrated based on the model dataset to ensure the continuity of the dataset. Please check the paper for detailed information.

Zheng Yijing, Maggie Chel Gee Ooi, Liew Juneng, Hin Boo Wee, Mohd Talib Latif, Mohd Shahrul Mohd Nadzir, Norfazrin Mohd Hanif et al. “Assessing the impacts of climate variables on long-term air quality trends in Peninsular Malaysia.” Science of the total environment (2023): 166430.