API Response
Data Sources
Forecast is based on the 11 kilometer CAMS European air quality forecast and the 40 kilometer CAMS global atmospheric composition forecasts. The European and global domain are not coupled and may show different forecasts.
| Data Set | Region | Spatial Resolution | Temporal Resolution | Data Availability | Update frequency |
|---|---|---|---|---|---|
| CAMS European Air Quality Forecast | Europe | 0.1° (~11 km) | 1-Hourly | October 2023 onwards | Every 24 hours, 4 days forecast |
| CAMS European Air Quality Reanalysis | Europe | 0.1° (~11 km) | Hourly | 2013 onwards | - |
| CAMS global atmospheric composition forecasts | Global | 0.25° (~25 km) | 3-Hourly | August 2022 onwards | Every 12 hours, 5 days forecast |
| CAMS Global Greenhouse Gas Forecast | Global | 0.1° (~11 km) | 3-Hourly | November 2024 onwards | Every 24 hours, 5 days forecast |
API Documentation
The API endpoint /v1/air-quality accepts a geographical coordinate, a list of weather variables and responds with a JSON hourly air quality forecast for 5 days. Time always starts at 0:00 today.
All URL parameters are listed below:
| Parameter | Format | Required | Default | Description |
|---|---|---|---|---|
| latitude, longitude | Floating point | Yes | Geographical WGS84 coordinates of the location. Multiple coordinates can be comma separated. E.g. &latitude=52.52,48.85&longitude=13.41,2.35. To return data for multiple locations the JSON output changes to a list of structures. CSV and XLSX formats add a column location_id. | |
| hourly | String array | No | A list of weather variables which should be returned. Values can be comma separated, or multiple &hourly= parameter in the URL can be used. | |
| current | String array | No | A list of variables to get current conditions. | |
| domains | String | No | auto | Automatically combine both domains auto or specifically select the European cams_europe or global domain cams_global. |
| timeformat | String | No | iso8601 | If format unixtime is selected, all time values are returned in UNIX epoch time in seconds. Please note that all timestamp are in GMT+0! For daily values with unix timestamps, please apply utc_offset_seconds again to get the correct date. |
| timezone | String | No | GMT | If timezone is set, all timestamps are returned as local-time and data is returned starting at 00:00 local-time. Any time zone name from the time zone database is supported. If auto is set as a time zone, the coordinates will be automatically resolved to the local time zone. For multiple coordinates, a comma separated list of timezones can be specified. |
| past_days | Integer (0-92) | No | 0 | If past_days is set, yesterday or the day before yesterday data are also returned. |
| forecast_days | Integer (0-7) | No | 5 | Per default, 5 days are returned. Up to 7 days of forecast are possible. |
| forecast_hours past_hours | Integer (>0) | No | Similar to forecast_days, the number of timesteps of hourly data can controlled. Instead of using the current day as a reference, the current hour is used. | |
| start_date end_date | String (yyyy-mm-dd) | No | The time interval to get weather data. A day must be specified as an ISO8601 date (e.g. 2022-06-30). | |
| start_hour end_hour | String (yyyy-mm-ddThh:mm) | No | The time interval to get weather data for hourly data. Time must be specified as an ISO8601 date (e.g. 2022-06-30T12:00). | |
| cell_selection | String | No | nearest | Set a preference how grid-cells are selected. The default land finds a suitable grid-cell on land with similar elevation to the requested coordinates using a 90-meter digital elevation model. sea prefers grid-cells on sea. nearest selects the nearest possible grid-cell. |
| apikey | String | No | Only required to commercial use to access reserved API resources for customers. The server URL requires the prefix customer-. See pricing for more information. |
Additional optional URL parameters will be added. For API stability, no required parameters will be added in the future!
Hourly Parameter Definition
The parameter &hourly= accepts the following values. Most weather variables are given as an instantaneous value for the indicated hour. Some variables like precipitation are calculated from the preceding hour as an average or sum.
| Variable | Valid time | Unit | Description |
|---|---|---|---|
| pm10 pm2_5 | Instant | μg/m³ | Particulate matter with diameter smaller than 10 µm (PM10) and smaller than 2.5 µm (PM2.5) close to surface (10 meter above ground) |
| carbon_monoxide nitrogen_dioxide sulphur_dioxide ozone | Instant | μg/m³ | Atmospheric gases close to surface (10 meter above ground) |
| carbon_dioxide | Instant | ppm | CO2 close to surface (10 meter above ground) |
| ammonia | Instant | μg/m³ | Ammonia concentration. Only available for Europe. |
| aerosol_optical_depth | Instant | Dimensionless | Aerosol optical depth at 550 nm of the entire atmosphere to indicate haze. |
| methane | Instant | μg/m³ | Methane close to surface (10 meter above ground) |
| dust | Instant | μg/m³ | Saharan dust particles close to surface level (10 meter above ground). |
| uv_index uv_index_clear_sky | Instant | Index | UV index considering clouds and clear sky. See ECMWF UV Index recommendation for more information |
| alder_pollen birch_pollen grass_pollen mugwort_pollen olive_pollen ragweed_pollen | Instant | Grains/m³ | Pollen for various plants. Only available in Europe as provided by CAMS European Air Quality forecast. |
| european_aqi european_aqi_pm2_5 european_aqi_pm10 european_aqi_nitrogen_dioxide european_aqi_ozone european_aqi_sulphur_dioxide | Instant | European AQI | European Air Quality Index (AQI) calculated for different particulate matter and gases individually. The consolidated european_aqi returns the maximum of all individual indices. Ranges from 0-20 (good), 20-40 (fair), 40-60 (moderate), 60-80 (poor), 80-100 (very poor) and exceeds 100 for extremely poor conditions. |
| us_aqi us_aqi_pm2_5 us_aqi_pm10 us_aqi_nitrogen_dioxide us_aqi_ozone us_aqi_sulphur_dioxide us_aqi_carbon_monoxide | Instant | U.S. AQI | United States Air Quality Index (AQI) calculated for different particulate matter and gases individually. The consolidated us_aqi returns the maximum of all individual indices. Ranges from 0-50 (good), 51-100 (moderate), 101-150 (unhealthy for sensitive groups), 151-200 (unhealthy), 201-300 (very unhealthy) and 301-500 (hazardous). |
JSON Return Object
On success a JSON object will be returned.
"latitude": 52.52,
"longitude": 13.419,
"elevation": 44.812,
"generationtime_ms": 2.2119,
"utc_offset_seconds": 0,
"timezone": "Europe/Berlin",
"timezone_abbreviation": "CEST",
"hourly": {
"time": ["2022-07-01T00:00", "2022-07-01T01:00", "2022-07-01T02:00", ...],
"pm10": [1, 1.7, 1.7, 1.5, 1.5, 1.8, 2.0, 1.9, 1.3, ...]
},
"hourly_units": {
"pm10": "μg/m³"
},
| Parameter | Format | Description |
|---|---|---|
| latitude, longitude | Floating point | WGS84 of the center of the weather grid-cell which was used to generate this forecast. This coordinate might be a few kilometers away from the requested coordinate. |
| generationtime_ms | Floating point | Generation time of the weather forecast in milliseconds. This is mainly used for performance monitoring and improvements. |
| utc_offset_seconds | Integer | Applied timezone offset from the &timezone= parameter. |
| timezone timezone_abbreviation | String | Timezone identifier (e.g. Europe/Berlin) and abbreviation (e.g. CEST) |
| hourly | Object | For each selected weather variable, data will be returned as a floating point array. Additionally a time array will be returned with ISO8601 timestamps. |
| hourly_units | Object | For each selected weather variable, the unit will be listed here. |
Errors
In case an error occurs, for example a URL parameter is not correctly specified, a JSON error object is returned with a HTTP 400 status code.
"error": true,
"reason": "Cannot initialize WeatherVariable from invalid String value tempeture_2m for key hourly"
Citation & Acknowledgement
METEO FRANCE, Institut national de l'environnement industriel et des risques (Ineris), Aarhus University, Norwegian Meteorological Institute (MET Norway), Jülich Institut für Energie- und Klimaforschung (IEK), Institute of Environmental Protection – National Research Institute (IEP-NRI), Koninklijk Nederlands Meteorologisch Instituut (KNMI), Nederlandse Organisatie voor toegepast-natuurwetenschappelijk onderzoek (TNO), Swedish Meteorological and Hydrological Institute (SMHI), Finnish Meteorological Institute (FMI), Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) and Barcelona Supercomputing Center (BSC) (2022): CAMS European air quality forecasts, ENSEMBLE data. Copernicus Atmosphere Monitoring Service (CAMS) Atmosphere Data Store (ADS). (Updated twice daily).
All users of Open-Meteo data must provide a clear attribution to CAMS ENSEMBLE data provider as well as a reference to Open-Meteo.