China Air Quality Index Search Engine Raw Data Archive
Search Station:
Search One Hour AQI:
Station: Date and time:
Search Multiple Days AQI:
Station: From: To:
Enter a province/city name (Romanized pinyin) to see all the monitoring stations in that province/city.
e.g. Beijing; Guangdong *If province returns nothing, try city.
You may leave Station blank and pick a date and time to see air quality index for all the stations at a certain time. Or just enter a station and see all the index for that station.
You may leave Station blank and pick two dates to see all the air quality index for all the stations in that period. Or enter a station and see its index in the period.


The US embassy in Beijing regularly posts automated air quality measurements at @beijingair on Twitter. On 18 November 2010, the feed described the PM2.5 measurement as "crazy bad" after registering a reading in excess of 500 for the first time. This description was later changed to "beyond index", a level which recurred in February, October, and December 2011. (source: Pollution in China,

In June 2012, following strongly divergent disclosures of particulate levels between the Observatory and the US Embassy, Chinese authorities asked foreign consulates to stop publishing "inaccurate and unlawful" data. Since then, more and more organizations started setting up their PM2.5 monitoring stations across China. as part of, has been posting hourly air quality index data in China to the public.

China Air Quality Index (AQI) Search Engine is developed by and hosted at the Center for Geographic Analysis at Harvard University, to retrieve as many air quality measurements as possible from the major sources and re-organize the data for environment research uses.

Data available on this site has been collected since February 7, 2014.

The data is made available for public use as provided by the owners and operators of the monitoring equipment, and presented by and websites. This collection of data represents only a sampling of the air quality measurements recorded at the sources. It is provided with no warranty *for academic, non-commercial use only* and with the sole intention of contributing data to scientific analysis by anyone who is interested in the public health consequences of air pollution.