Weather and climate · by OpenAQ (non-profit)

OpenAQ

An open platform that collects air-quality measurements (PM2.5, PM10, ozone, NO2 and more) from government monitors and low-cost sensors worldwide and serves them through a free keyed REST API and a key-less daily CSV archive on AWS S3.

It puts readings from many countries' monitoring networks into one schema, so you can compare the air in two cities with the same query.

LiveAPIDownloadCommercial: conditions

Open openaq.org ↗ agent.md

For your project

Official API: Official API · Free tier Free key: 60 requests/minute and 2,000/hour; higher limits under a custom agreement with pricing on request
“Our open API allows applications to connect directly to OpenAQ data.” openaq.org/
Key: Needed
“Include your API key in the X-API-Key header of each request.” docs.openaq.org/using-the-api/api-key
Formats: JSON, CSV
Data download: Yes csv.gz
“The bucket root url is https://openaq-data-archive.s3.amazonaws.com/” docs.openaq.org/aws/about
License: per-source licences (OpenAQ Terms of Use) Air-quality data aggregated from many providers; each source's licence (exposed via the /v3/licenses resource) decides commercial use and attribution; OpenAQ must also be credited
Commercial use: Commercial use with conditions
“Each license details permissions and restrictions, such as whether attribution is required and whether commercial use, modifications, or redistribution are allowed.” docs.openaq.org/resources/licenses
Credit: Credit required
“Attribution to OpenAQ as the source data is also required when using OpenAQ services for accessing the data.” docs.openaq.org/about/terms
Embedding: Embedding with conditions
“we provide no assurance that the data provided may be used free of any third-party claims.” docs.openaq.org/about/terms
Using the website: Free

Read on OpenAQ's own pages on Oct 23, 2026 · license or terms · API docs. Check the license page before you ship.

For your agent

A request your code or agent can make (add your key):

https://openaq-data-archive.s3.amazonaws.com/records/csv.gz/locationid=2178/year=2022/month=05/location-2178-20220503.csv.gz

The v3 API returns 401 without an X-API-Key header (free key from explore.openaq.org); for bulk history skip the API and read the key-less S3 archive (records/csv.gz/locationid=/year=/month=), and check each location's license via /v3/licenses before commercial use.
Get a free API key and send it as X-API-Key; stay within 60 requests/minute and 2,000/hour, and stop jobs you no longer need.
Credit OpenAQ and the original data provider(s) as their terms require.
Check each source's licence (commercialUseAllowed, attributionRequired) before commercial use.

Paste into your agent: Read https://agentgid.com/resources/openaq/agent.md before using OpenAQ.

What you can build

A neighbourhood air-quality widget that finds the nearest PM2.5 sensors with /v3/locations?coordinates=&radius= and shows the latest values with source credit.
A city-comparison dashboard that loads a year of daily CSV files from the S3 archive into DuckDB and charts PM2.5 against WHO guideline levels.
A wildfire-smoke alert bot that polls the latest readings for selected locations and messages users when PM2.5 crosses a threshold.

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