That blanket over Bejing? Despite what the government wants to tell you, it isn't just inclement weather. A new report from the US Embassy air monitor rates the air in Beijing as "beyond index", with 522 micrograms of particulate pollutants per cubic meter of air, according to a new report on France24.com.

Despite authorities in China decreeing that the air quality is simply "fog," and "perfectly save 80% of the time" the US report states that the air is only good 13 days out of the year.

Citizens and expats alike are turning to Twitter to check out @BeijingAir, an account with more than 15,000 followers, to find the actual data on air quality. Air monitors on the embassy roof have found particles large enough to penetrate human lungs, up to 2.5 micrometers in size. This technology is more advanced than the ones local authorities use to measure pollution.

Two years ago, Chinese officials asked the US Embassy to stop tweeting about pollution in Beijing on the grounds that the information was "confusing" and could have "social consequences", according to a confidential US State Department cable made public by WikiLeaks.

Chinese officials say that they will be able to measure the particles themselves by 2015.

"It is advisable not to go out in such weather, especially when there is this hazy fog, but at the same time you have to work. For several years now, I have been wearing a surgical mask every time I am on the street or going to my workplace," a Beijing resident was quoted telling France24.com.

Those visiting the city are cautioned to limit time outside and to use anti-pollution masks that filter out fine air particles when traveling outdoors.