Beijing Air Quality: pm2.5

So how was 2016 for PM2.5 in Beijing?
Short answer: BIG improvement. The average has dropped from 158 in 2014 to 142
in 2015 to 133 in 2016! The best 2 months in the last 10 years were February
and August 2016, and February, with an average of 93.6, was the first month
to average under 100 since my records started in 2008. 4 of the top 10 months
in that time came in 2016, and 7 of the top 10 have been in 2015 and 2016.
See monthly statistics here
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New! Beijing smog forecast from
Next time with good air: Sat 08-19 at 11:00
Next morning with clean air: Thu 08-24
Last updated at 2017-08-18 23:00 EDT

More complete forecast information can be found at

Android App! My (un)employment situation has given me both time to program my own stuff and an impetus to work on new things to enhance my experience. To learn about Android programming I made an app for displaying the most recent readings on an Android phone. I am not going to release it officially, but will make the debug version available here if anyone cares to download it. You can also preview it online.

Scale: US China What does this mean?
Automatic refresh:

Data for previous years can be accessed in csv form from the summary pages

No data found from 2009-01-03 00:00 to 2009-01-4 0:00
Wired had an article about how the US Embassy AQI tweets helped speed up China's monitoring and addressing its pollution problem. I'd like to think my page also helped.
The original purpose of this site was to save historical data, which at the time the US Embassy did not supply. A while ago they started making it available too. The site is They have some explicit restrictions and limitations on use of their data.

More information on my site can be found here, or visit my main site. That page also has links where you can get history updates or link to a graphics label that can be put on web pages. And, for ubuntu users, there is an app that shows the current API in the top bar.

PM2.5 measurements are commonly given in 2 different units, ug/m3 and AQI. The difference between them is explained here, and here is a calculator that will let you convert one to the other. AQI only goes up to 500, what do those "crazy bad" readings mean?

Here is a story about a guy who has another, more qualitative way to show the data: every day he takes a picture of the same scene outside his window. His blog (in Chinese) is at

Daily 2014 images

Daily 2015 images

Does not work well with IE, but does with Chrome, Firefox, and Opera - and I don't care about IE.