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About the API

The OpenAQ API provides open access to global air quality data, following REST principles with resource-oriented URLs, standard HTTP response codes, and JSON-formatted responses. OpenAQ focuses on criteria air pollutants, primarily aggregating PM2.5, PM10, SO2, NO2, CO, O3, BC, relative humidity and temperature measurement data. For a limited set of locations, we have data for PM1, PM4, CO2, NO, NOx, CH4 & UFP.

The data on OpenAQ do not represent all air quality monitoring data in the world; they are data that OpenAQ has discovered or been introduced to and that are publicly available. We welcome new data contributions.

All data accessed through the API is public. However, you are responsible for complying with applicable third-party terms. Please see our Terms of Use for very important information on intellectual property, allowable and considerate use, and more.

This documentation guide covers the OpenAQ API version 3. OpenAPI reference documentation for version 1 and 2 is still available in the reference section but all other content in this guide pertains to version 3. To get started, explore the available endpoints and consult the documentation for guidance.

This repository of global air quality data is brought to you by OpenAQ, a nonprofit organization founded in the U.S. OpenAQ was the first to aggregate ground-level ambient air quality data on an open-source platform. We provide unique value due to a combination of attributes that make these data easily accessible, interoperable, interpretable and actionable. We:

  • harmonize the data into a single, uniform format so that they are easily comparable
  • share the data in physical units rather than as an air quality index
  • host near real-time and historical data
  • share “metadata” (the data that provides the context for individual data points)
  • make the data available programmatically via an API
  • keep the underlying data-fetching software fully open
  • provide tools for users of all abilities to access and use the data

If you value this service, please consider making a donation to sustain the OpenAQ platform far into the future.