Questions as clear skies in Beijing coincide with NPC, CPPCC meetings

The return of joggers, mountains on the western horizon and smiles on the unmasked faces of passers-by heralded a huge improvement in Beijing's air quality yesterday.

And to no doubt the satisfaction of the central government, crisp, smog-free air was forecast to continue into today, as National People's Congress (NPC) delegates gather for the opening of their annual meeting.

The conditions were idyllic compared with the hazy norm in the past few months, as the temperature rose to 16 degrees Celsius and the PM2.5 pollution index fell as low as 23 micrograms per cubic metre, well into the "excellent" range, according to the United States embassy's readings. The official figures were even more rosy, with the PM2.5 reading falling to 10. Many days in recent months have seen the level exceed 200.

The National Meteorological Centre estimated that conditions would remain dry and sunny this morning.

With such a marked improvement in air quality, many residents speculated that Beijing must have taken measures to reduce pollution for the annual meetings of the NPC and the Chinese People's Political Consultative Conference (CPPCC), during which the nation's new leaders will be appointed.

It was reminiscent of 2008, when the air quality dramatically improved for the Beijing Summer Olympics, when the government shut down many factories in the region.