Since the begining, the World Air Quality Index (WAQI) project team has always been keen on providing a transparent Air Qualitty Infomration to the world citizens.
The WAQI project has also always been keen on providing historical Air Quality Data to relevant institutions and organizations working in the area of environmental awareness, air quality monitoring, as well as health and epidemiological studies. Here are few of our partners and colleagues to which we have been providing historical air quality data information:

In order to make the historical Air Quality Data dissemination even more relevant, the World Air Quality Index team has been investigating with the most relevant international institutions the possibility to setup an open data framework. Here are fews of the institutions we have engaged:

• WHO - World Health Organization
• UNEP - United Nation Environmental Program
• UNIDO - United Nation Industrial Development Organization
• WMO - World Meteorological Organization
• GEO - Group on Earth Observations
• WRI - World Resource Institute
• CCA - Climate & Clean Air Coalition

The open data framework objective is to provide unlimited and free access the world historical and real-time Air Quality data from the 100+ countries covered on aqicn.org Everyone - both institutions as well as citizens - agrees that this is not only a good idea, but that it should *just* happen.

The daily average air quality data for all of the stations can be downloaded freely from the form below. Note that all the figures are converted to AQI using the US EPA standard: i.e. we do not publish the raw concentrations, but only the AQI.


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Notes:
The Air Quality data is currently only available for the past 7 years, from 2014 until now. If you need data before this period, we recommend to either contact the originating EPA, or consider using estimates based on remote sensing data (WHO).

In the above data, we publish the "Individual pollutant" Air Quality index. For instance, if you check the figures for PM_2.5, they correspond to the PM_2.5 individual AQI (noted as AQI_PM2.5). If you want to calculate the overall AQI, aka composite AQI, you need to take the maximum of all individual AQI:

AQI = max( AQI_PM2.5, AQI_PM10, AQI_O3, ...)
Last if you need the real-time data instead, try the API page. It's free too!

If the above data does not work for you, and you are from an international institution, organization or university you can register your interest with the form below. Note that this registration is only at intent level, for us to consolidate the list of all interested parties, and does not bound you, nor the world air quality index project, to any obligations.

Institution & University Registration - subscription form

Your information

Enter your name - eg "John Doe"

Enter your email address - eg "john.doe@mail.com"

Enter your organization - eg "Harvard Business School"

Enter your position - eg "Student, Researcher, Head"

Data information

Data Period - eg "June 2018" to "August 2018"

Start date

Stop date

Data Frequency - eg "Daily"

Frequency

Daily

Hourly

Monthly

Weekly

Yearly

Enter the name of the stations you need the data for - eg "Beijing"
Name of a station, eg Beijing

Tell us a bit more

Write few words about your request - eg: "I would like to get the daily max AQI for Berlin for Winter 2014", "I would like to know the hourly concentration of SO2 for Civil Lines in Delhi on June 18th 2015", "I would like to support your project and give you hand", ..

The open data framework would not be possible without the work from the worldwide EPA, which should get the credits for their monitoring programs.

About the Air Quality Levels

AQI	Air Pollution Level	Health Implications	Cautionary Statement (for PM2.5)
0 - 50	Good	Air quality is considered satisfactory, and air pollution poses little or no risk	None
51 -100	Moderate	Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.	Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion.
101-150	Unhealthy for Sensitive Groups	Members of sensitive groups may experience health effects. The general public is not likely to be affected.	Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion.
151-200	Unhealthy	Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects	Active children and adults, and people with respiratory disease, such as asthma, should avoid prolonged outdoor exertion; everyone else, especially children, should limit prolonged outdoor exertion
201-300	Very Unhealthy	Health warnings of emergency conditions. The entire population is more likely to be affected.	Active children and adults, and people with respiratory disease, such as asthma, should avoid all outdoor exertion; everyone else, especially children, should limit outdoor exertion.
300+	Hazardous	Health alert: everyone may experience more serious health effects	Everyone should avoid all outdoor exertion

To know more about Air Quality and Pollution, check the wikipedia Air Quality topic or the airnow guide to Air Quality and Your Health.

For very useful health advices of Beijing Doctor Richard Saint Cyr MD, check www.myhealthbeijing.com blog.