A photovoltaic power station in Suichang county, Lishui, Zhejiang province, reflects the region's commitment to cleaner air. [Photo provided to chinadaily.com.cn]

East China's Zhejiang province saw strong environmental performance in May, with Lishui, Zhoushan, and Taizhou ranking among the top 20 cities nationwide for overall air quality, according to data released by the Ministry of Ecology and Environment.

In terms of PM2.5 concentration, Zhoushan, Ningbo, and Lishui also made the national top 20 list for cities with the lowest levels of fine particulate matter.

Nationally, the average PM2.5 concentration across 339 major cities was 24.5 micrograms per cubic meter, up 8.9 percent year-on-year. The proportion of days with "good" or "excellent" air quality reached 81.9 percent, a 3.7 percentage point increase from the same period last year.

Within Zhejiang, the Department of Ecology and Environment of Zhejiang Province reported that the 11 prefecture-level cities recorded an average of 79.8 percent good air quality days in May.