Documentation

WAQI — World Air Quality Index API

Query air quality data from https://waqi.info (website: https://aqicn.org). WAQI and AQICN are the same project — WAQI is the API name, AQICN is the website.

Setup

API token is in env var WAQI_API_TOKEN.

TOKEN="$WAQI_API_TOKEN"

API Endpoints

Base URL: https://api.waqi.info

All requests append ?token=$TOKEN.

1. City Feed (by name)

curl -s "https://api.waqi.info/feed/{city}/?token=$WAQI_API_TOKEN"

Examples: feed/beijing/, feed/tokyo/, feed/shanghai/

2. Geo Feed (by coordinates)

curl -s "https://api.waqi.info/feed/geo:{lat};{lng}/?token=$WAQI_API_TOKEN"

Returns the nearest monitoring station to the given coordinates.

3. Station Search

curl -s "https://api.waqi.info/search/?keyword={query}&token=$WAQI_API_TOKEN"

Returns matching stations with current AQI. Use to find station names or discover monitoring coverage.

4. Map Stations (bounding box)

curl -s "https://api.waqi.info/v2/map/bounds/?latlng={lat1},{lng1},{lat2},{lng2}&networks=all&token=$WAQI_API_TOKEN"

Returns all stations within a bounding box. Useful for comparing AQI across a region.

Response Structure

Key fields in a feed response (.data):

• .aqi — Current AQI value (US EPA standard)
• .city.name — Station/city name
• .city.geo — [lat, lng]
• .dominentpol — Dominant pollutant (pm25, pm10, o3, etc.)
• .iaqi — Individual pollutant readings: .pm25.v, .pm10.v, .o3.v, .no2.v, .so2.v, .co.v
• .iaqi.t.v — Temperature, .iaqi.h.v — Humidity, .iaqi.w.v — Wind
• .time.iso — Observation time (ISO 8601 with timezone)
• .forecast.daily — Multi-day forecasts with .pm25[], .pm10[], .o3[], .uvi[]
  • Each entry: {avg, day, max, min}

AQI Scale (US EPA)

Tips

• China coverage is excellent — most prefecture-level cities have multiple stations
• Geo query returns nearest station — for remote areas the nearest station may be 50+ km away
• Forecast data varies by station — major cities have 7-day PM2.5/PM10 forecasts; smaller stations may not
• Rate limit: 1000 req/min on free tier
• Batch pattern:

for coords in "39.90;116.40" "40.97;115.27" "36.65;116.98"; do
  curl -s "https://api.waqi.info/feed/geo:${coords}/?token=$WAQI_API_TOKEN" | \
    jq -r '[.data.aqi, .data.city.name] | @tsv'
done