Due to the continuous increase of environmental pollution in recent years, the high concentration of particulate matters in air has greatly reduced the amount of solar radiation that can reach the earth, and this reduction has a direct effect on the use of solar energy in buildings. To quantify this attenuation effect, historical meteorological data collected from five regions, namely, Beijing, Tianjin, Jinan, Xi'an and Zhengzhou, in China from 2014 to 2016 were used to investigate the correlation between clearness index (reflecting available radiation) and air quality index (reflecting pollution level). The analysis results have revealed that higher air quality index would result in lower clearness index, and the sunny days gave higher decreasing rate than cloudy days. For all five regions, their monthly clearness index attenuation showed higher values in winter than that in summer. The monthly solar radiation attenuation, however, showed an opposite trend, due to higher solar altitude in summer. Additionally, different regions had different annual solar radiation attenuation ratio, with Tianjin giving the highest of 6.56% (651.17 MJ/m(2)), followed by Beijing (3.92%, 410.08 MJ/m(2)), Xi'an (4.94%, 510.42 MJ/m(2)), Zhengzhou (3.99%, 427.64 MJ/m(2)) and Jinan (2.69%, 284.66 MJ/m(2)). (C) 2020 Elsevier Ltd. All rights reserved.