Blue skies are shining on Beijingers.
The city experienced its best month of air quality since 2000 with 23 blue-sky days in April.
Experts credit measures to protect the environment and the sluggish economic slowdown for the improvement.
"Thanks to consistent environmental protection measures such as traffic control, green construction and a ban on heavy-polluting vehicles, we have achieved great improvement in the capital's air quality," Du Shaozhong, deputy director of the Beijing municipal environmental protection bureau, told China Daily on Friday.
Air quality is measured by the air pollution index (API), which monitors the level of five airborne pollutants.
A blue-sky day is when the city's API falls below 100, meaning there are no health implications.
With only seven slightly polluted days, Beijing saw 23 clean days last month, four more than the same period last year.
And for the first time in nine years there was no day with an API over 150, a level when people with breathing or heart problems should limit outdoor activities. The concentration of particulates in the air also dropped 25 percent from the previous year.
Besides strict environmental protection measures, experts think the global economic slowdown might be playing a positive role in environmental protection.
Zhu Tong, an environment professor with Peking University, told China Daily on Friday that heavy industry has decreased production in many polluting factories, which benefits the air.
"Most companies in heavy industry are seeing fewer orders. The output of the Shougang Group this year so far equals the same period during the Olympics," said Wang Dawei, head of the air quality control division of the Beijing municipal environmental protection bureau.
In the first season this year, the added value for ferrous metal and chemistry manufacturing in the capital was 3.36 billion yuan ($490 million) and 1.85 billion yuan, a year-on-year decrease of 18.1 percent and 17.9 percent respectively.
With all these factors working together, Beijing has seen 96 blue-sky days so far this year, putting it well ahead of pace to achieve its target of 260 blue-sky days for the year.
Prior to the 2008 Olympics, many high-polluting plants like Shougang Group, which produces iron and steel, were moved out of the city and gas stations were revamped to curb petroleum vaporization.
All these measures helped the capital's number of blue-sky days rise to 274 last year from 100 in 1999, when the government launched its anti-pollution campaign.