Haikou’s Evergreen Park
According to the latest report on air quality in 74 Chinese cities, which was released by Ministry of Environmental Protection, Haikou was once again ranked number one for best air quality in China.
Of the 74 sampled cities, they are mainly located in the Beijing-Tianjin-Hebei Region and the Yangtze River Delta/Pearl River Delta regions. 
The Ministry of Environmental Protection started releasing its monthly report on 74 Chinese cities in 2013, when the revised air quality standards came into enforcement.
In May, the top 10 cities with the best air quality were Haikou, Zhuhai, Zhongshang, Shenzhen, Jiangmen, Huizhou, Dongguan, Lhasa, Harbin and Nanning, and the cities with worst air quality were Xingtai, Tangshan, Nanjing, Handan, Shijiazhuang, Hengshui, Changzhou, Jinan, Zhenjiang and Baoding.