Getting Started

The API has two main end points:

/forecast
/measurements

As an example, for a forecast of the parameters temperature (tt), rain (rr), and total cloud cover (tcc), the URL looks as follows:

https://api.meteotest.ch/api/v1/forecast
?lat=46.9534
&lon=7.4237
&parameters=tt,rr,tcc
&timeFrom=now
&timeTo=+24hours

Access token.
To access the API, you need a valid access token that you'll have to send as part of the HTTP header (see example below). Soon, you'll be able to manage subscriptions on this website. In the meantime, if you're interested in a demo or real subscription, send us an email: office@meteotest.ch.

Here's a working example using cURL:

curl -G --header "Authorization: Bearer INSERT-YOUR-TOKEN" \
    --data "lat=46.9534" \
    --data "lon=7.4237" \
    --data "parameters=tt,rr,tcc" \
    --data "timeFrom=now" \
    --data-urlencode "timeTo=+6hours" \
    "https://api.meteotest.ch/api/v1/forecast" | json_pp

Response:

{
    "issuetime": "2022-10-24T21:30:33Z",
    "timeseries": {
        "frequency": "1hours",
        "index": [
            "2022-10-24T22:00:00Z",
            "2022-10-24T23:00:00Z",
            "2022-10-25T00:00:00Z",
            "2022-10-25T01:00:00Z",
            "2022-10-25T02:00:00Z",
            "2022-10-25T03:00:00Z"
        ],
        "values": {
            "rr": [
                0.0,
                0.0,
                0.0,
                0.0,
                0.0,
                0.0
            ],
            "tcc": [
                75.0,
                75.0,
                75.0,
                75.0,
                75.0,
                87.5
            ],
            "tt": [
                12.5,
                12.2,
                11.9,
                11.6,
                11.4,
                11.2
            ]
        },
        "lat": 46.9534,
        "lon": 7.4237,
        "stepType": {
            "rr": "AVERAGE",
            "tcc": "AVERAGE",
            "tt": "AVERAGE"
        }
    },
    "request": {
        "azimuth": 180,
        "cddCriticalTemperatureOutside": 35.0,
        "hddCriticalTemperatureInside": 20.0,
        "hddCriticalTemperatureOutside": 12.0,
        "horizon": null,
        "inclination": 30,
        "installedCapacity": null,
        "lat": 46.9534,
        "lon": 7.4237,
        "parameters": [
            {
                "description": "Precipitation rate",
                "shortname": "rr",
                "unit": {
                    "description": "mm/h",
                    "string": "mm/h",
                    "uid": "mm_per_h"
                }
            },
            {
                "description": "Total cloud coverage (100% = overcast)",
                "shortname": "tcc",
                "unit": {
                    "description": "%",
                    "string": "%",
                    "uid": "percent"
                }
            },
            {
                "description": "Air temperature",
                "shortname": "tt",
                "unit": {
                    "description": "\u00b0C",
                    "string": "\u00b0C",
                    "uid": "celsius"
                }
            }
        ],
        "resampleTo": null,
        "source": null,
        "timeFrom": "2022-10-24T21:30:33Z",
        "timeTo": "2022-10-25T03:30:33Z"
    }
}

If you're interested in measurements rather than forecasts, use the same URL arguments with end point /measurements. Example:

curl -G --header "Authorization: Bearer INSERT-YOUR-TOKEN" \
    --data "lat=46.9534" \
    --data "lon=7.4237" \
    --data "parameters=tt,rr,ff" \
    --data "timeFrom=2022-09-01T00:00:00Z" \
    --data "timeTo=2022-10-01T00:00:00Z" \
    "https://api.meteotest.ch/api/v1/measurements"

The API automatically selects the weather model (or data source for measurements) that best suits the requested location and parameters. You can query a particular weather model or data source by using the source URL argument. As an example, to query the Cosmo1 model for Switzerland, set

&source=cosmo1-switzerland

Tutorial for Solar ☀️ Applications

The API provides several parameters relevant for the monitoring and operation of PV plants. See parameters for a complete list of available parameters, the most important of which are

gh (global radiation),
gk (global radiation on inclined plane), and
e (energy output per kWp installed).

For operations, the API provides satellite-based radiation data with a temporal resolution of 15 minutes. To query radiation data for the past 24 hours:

curl -G --header "Authorization: Bearer INSERT-YOUR-TOKEN" \
    --data "lat=46.9534" \
    --data "lon=7.4237" \
    --data "parameters=gh,gk,e" \
    --data "inclination=30" \
    --data "azimuth=180" \
    --data "timeFrom=-24hours" \
    --data "timeTo=now" \
    --data "source=solarsat" \
    "https://api.meteotest.ch/api/v1/measurements"

When you plot the response using your favourite programming language, it would look something like this:

The API also provides satellite-based radiation nowcasting with a temporal resolution of 15 minutes. To query radiation data for the next 3 hours:

curl -G --header "Authorization: Bearer INSERT-YOUR-TOKEN" \
    --data "lat=46.9534" \
    --data "lon=7.4237" \
    --data "parameters=gh,gk,e" \
    --data "inclination=30" \
    --data "azimuth=180" \
    --data "timeFrom=now" \
    --data-urlencode "timeTo=+3hours" \
    --data "source=cloudmove" \
    "https://api.meteotest.ch/api/v1/forecast"

The default forecast with hourly resolution, i.e., the forecast you get when you don't specify a particular source=, also provides the solar parameters. To query radiation data for the next 72 hours:

curl -G --header "Authorization: Bearer INSERT-YOUR-TOKEN" \
    --data "lat=46.9534" \
    --data "lon=7.4237" \
    --data "parameters=gh,gk,e" \
    --data "inclination=30" \
    --data "azimuth=180" \
    --data "timeFrom=now" \
    --data-urlencode "timeTo=+72hours" \
    "https://api.meteotest.ch/api/v1/forecast"

API Docs

/forecast and /measurements

The /forecast and /measurements endpoints provide the following GET arguments:

Fields with a ☀️ are relevant only if you request one (or several) of the following parameters:
gk, dh, bh, dni, ghMax, e, eTotal

Name	Description
lat * required (number)	query point, latitude Example: `47.545` Number range: `-90` ... `90`
lon * required (number)	query point, longitude Example: `7.54` Number range: `-180` ... `180`
altitude (number)	altitude in meters Example: `543` Number range: `-100` ... `10000`
parameters * required (string)	Comma-separated list of parameters. The following parameters are available: tt, ff, fx, dd, qff, rh, rr, sy, tcc, gh, gk, bh, dh, dni, e, e_total, hdd, cdd, gh_max. Example: `tt,rr,gh`
timeFrom * required (string)	Start time of request. Either RFC3339 UTC (YYYY-MM-DDThh:mm:ssZ), the string "now", or a relative date/time string (relative with respect to the current time). Examples of relative date/time strings (note that you have to url-encode the plus sign): `now` `+72hours` `-24hours` `+90minutes` `-30minutes` `+7days` `-3days` Example: `2020-01-01T00:00:00Z`
timeTo * required (string)	End time of request. See `timeFrom` for details. Example: `2020-01-01T00:00:00Z`
resampleTo (string)	Desired temporal resolution of response. Format: `NUMBERseconds\|minutes\|hours` Valid examples: `1seconds` `30seconds` `150seconds` `1minutes` `10minutes` `1hours` `12hours` `24hours` If omitted, the returned time series will have the original temporal resolution of the underlying data set. Example: `30minutes`
azimuth (number)	☀️ Azimuth of solar panel. Conventions: 0° = oriented towards the north 90° = oriented towards the east 180° = oriented towards the south 270° = oriented towards the west Example: `180` Number range: `0` ... `360` Default: `180`
inclination (number)	☀️ Inclination of the installed panels. 0° = horizontal, 90° = vertical. Example: `30` Number range: `0` ... `90` Default: `30`
horizon (string)	☀️ 12 integer values (elevation angle in degrees) that descibre the 360° horizon of location. The horizon is taken into account when computing special solar parameters. The 12 numbers are in the order north → east → south → west → north, i.e., 0°, 30°, 60°, ..., 300°, 330°. For example, `20,20,20,0,0,0,0,0,0,0,0,20` corresponds to a 20° horizon in the north and in the east. Example: `0,0,0,0,0,0,0,0,20,20,20,0`
installedCapacity (number)	☀️ Installed capacity of solar panel in kW, i.e., kWp (kilowatt peak). This argument is mandatory for parameter `e_total` and is being ignored for any other parameters. Example: `500` Number range: `0` ... `1000000000`
hddCriticalTemperatureInside (number)	Heating degree days: Critical inside temperatur in degrees celsius. This argument is only relevant if you request parameter `hdd`. Example: `19` Number range: `0` ... `50` Default: `20`
hddCriticalTemperatureOutside (number)	Heating degree days: Critical outside temperatur in degrees celsius. This argument is only relevant if you request parameter `hdd`. Example: `5` Number range: `-30` ... `30` Default: `12`
cddCriticalTemperatureOutside (number)	Cooling degree days: Critical outside temperatur in degrees celsius. This argument is only relevant if you request parameter `cdd`. Example: `35` Number range: `20` ... `60` Default: `35`
source (string)	Query forecast or measurements from a specific weather model or measurements source, respectively. See the documentation for more details. Example: `mos-mix`

Meta data (parameters, data sources)

Meta data of the API, i.e., the list of available parameters and data sources, can be queried with the following end points:

https://api.meteotest.ch/api/v1/parameters

Response:

{
    "parameters": [
        {
            "description": "Air temperature",
            "shortname": "tt",
            "unit": {
                "uid": "celsius",
                "string": "°C",
                "description": "°C"
            }
        },
        {
            "description": "dew point temperature",
            "shortname": "td",
            "unit": {
                "uid": "celsius",
                "string": "°C",
                "description": "°C",
            },
        },
        [...]
    ]
}

https://api.meteotest.ch/api/v1/sources

Response:

{
    "sources": {
        "forecast": [
            {
                "name": "mos-mix",
                "description": "Model Output Statistics (MOS). [...]"
                "bounding_boxes": [{"lower_left": {"lat": -90.0, "lon": -180.0}}],
                "timerange": "NOW -30 days ... NOW +216 hours",
                "title": "MOS MIX"
                "parameters": [
                    {
                        "description": "Global radiation (on the horizontal plane)",
                        "shortname": "gh",
                        "unit": {
                            "description": "W/m²",
                            "string": "W/m²",
                            "uid": "W_per_m2"
                        }
                    },
                    [...]
                ]
            },
            [...]
        ],
        "measurements": [
            [...]
        ]
    }
}

List of Weather Parameters

shortname	description	unit
tt	Air temperature	°C
td	dew point temperature	°C
rr	Precipitation rate	mm/h
rh	Relative humidity	%
gh	Global radiation (on the horizontal plane)	W/m²
ff	Wind speed	km/h
dd	Wind direction	° description: angle in degrees
fx	Wind gusts	km/h
qff	Mean sea level pressure	hPa description: hectopascal
tcc	Total cloud coverage (100% = overcast)	%
hdd	Heating degree days	°C
cdd	Cooling degree days	°C
sy	Weather symbol	weather_symbol description: Meteotest weather symbol code. 1: sunny, 2: light coverage, 3: strong coverage, 4: completely covered, 5: heat thunderstorms, 6: heavy precipitation, 7: snow fall, 8: fog, 9: sleet, 10: rain shower, 11: light precipitation, 12: snow shower, 13: front thunderstorms, 14: low stratus, 15: sleet shower.

For solar ☀️ industry applications, the following parameters are provided:

shortname	description	unit
gh	Global radiation (on the horizontal plane)	W/m²
gk	Global radiation on the inclined plane	W/m²
dh	Diffuse radiation on the horizontal plane	W/m²
bh	Direct radiation on the horizontal plane	W/m²
dni	Direct normal irradiation	W/m²
ghMax	Clear sky radiation	W/m²
e	Energy output per kWp installed	Wh/kWp description: Wh per kW peak installed
eTotal	Total/effective energy output	kWh description: Kilowatt-hours
tt	Air temperature	°C

List of Forecast Models

MOS MIX

Model Output Statistics (MOS). The forecast is based on the global weather forecasting models IFS (ECMWF) and GFS. The output of these global models is then statistically optimised using measurement data from weather stations. MOS MIX provides forecasts with high accuracy specifically for your location. Note that, in the context of our former product suite solarwebservices.ch, MOS MIX was called "SolarForecast" ☀️. Updated on an hourly basis.

Usage: &source=mos-mix

Frequency: 1 hours

Temporal range: NOW -30 days ... NOW +216 hours

Available parameters:

☀️ bh: Direct radiation on the horizontal plane [W/m²]
cdd: Cooling degree days [°C]
dd: Wind direction [°]
☀️ dh: Diffuse radiation on the horizontal plane [W/m²]
☀️ dni: Direct normal irradiation [W/m²]
☀️ e: Energy output per kWp installed [Wh/kWp]
☀️ eTotal: Total/effective energy output [kWh]
ff: Wind speed [km/h]
fx: Wind gusts [km/h]
gh: Global radiation (on the horizontal plane) [W/m²]
☀️ ghMax: Clear sky radiation [W/m²]
☀️ gk: Global radiation on the inclined plane [W/m²]
hdd: Heating degree days [°C]
qff: Mean sea level pressure [hPa]
rh: Relative humidity [%]
rr: Precipitation rate [mm/h]
sy: Weather symbol [weather_symbol]
tcc: Total cloud coverage (100% = overcast) [%]
td: dew point temperature [°C]
tt: Air temperature [°C]

Bounding box:

Cosmo 1km, Switzerland

Latest generation weather model with a spatial resolution of 1km. Run by MeteoSwiss. Updated every 3 hours.

Usage: &source=cosmo1-switzerland

Frequency: 1 hours

Temporal range: NOW -2 hours ... NOW +30 hours

Available parameters:

☀️ bh: Direct radiation on the horizontal plane [W/m²]
cdd: Cooling degree days [°C]
dd: Wind direction [°]
☀️ dh: Diffuse radiation on the horizontal plane [W/m²]
☀️ dni: Direct normal irradiation [W/m²]
☀️ e: Energy output per kWp installed [Wh/kWp]
☀️ eTotal: Total/effective energy output [kWh]
ff: Wind speed [km/h]
fx: Wind gusts [km/h]
gh: Global radiation (on the horizontal plane) [W/m²]
☀️ ghMax: Clear sky radiation [W/m²]
☀️ gk: Global radiation on the inclined plane [W/m²]
hdd: Heating degree days [°C]
qff: Mean sea level pressure [hPa]
rh: Relative humidity [%]
rr: Precipitation rate [mm/h]
sy: Weather symbol [weather_symbol]
tcc: Total cloud coverage (100% = overcast) [%]
td: dew point temperature [°C]
tt: Air temperature [°C]

Bounding box:

Global Forecast System

The Global Forecast System run by the United States' National Weather Service. Updated every 3 hours.

Usage: &source=gfs

Frequency: 3 hours

Temporal range: NOW -3 hours ... NOW +192 hours

Available parameters:

☀️ bh: Direct radiation on the horizontal plane [W/m²]
cdd: Cooling degree days [°C]
dd: Wind direction [°]
☀️ dh: Diffuse radiation on the horizontal plane [W/m²]
☀️ dni: Direct normal irradiation [W/m²]
☀️ e: Energy output per kWp installed [Wh/kWp]
☀️ eTotal: Total/effective energy output [kWh]
ff: Wind speed [km/h]
fx: Wind gusts [km/h]
gh: Global radiation (on the horizontal plane) [W/m²]
☀️ ghMax: Clear sky radiation [W/m²]
☀️ gk: Global radiation on the inclined plane [W/m²]
hdd: Heating degree days [°C]
qff: Mean sea level pressure [hPa]
rh: Relative humidity [%]
rr: Precipitation rate [mm/h]
sy: Weather symbol [weather_symbol]
tcc: Total cloud coverage (100% = overcast) [%]
tt: Air temperature [°C]

Bounding box:

CloudMove nowcasting system

Our shortest-term forecasting system CloudMove is based on a novel forecasting concept: using wind fields from weather models, the currently measured cloudiness is propagated into the future to forecast the radiation for (almost) any location in the world. Updated every 15 minutes.

Usage: &source=cloudmove

Frequencies: 10 minutes , 15 minutes

Temporal range: NOW -3 hours ... NOW +6 hours

Available parameters:

☀️ bh: Direct radiation on the horizontal plane [W/m²]
☀️ dh: Diffuse radiation on the horizontal plane [W/m²]
☀️ dni: Direct normal irradiation [W/m²]
gh: Global radiation (on the horizontal plane) [W/m²]
☀️ ghMax: Clear sky radiation [W/m²]
☀️ gk: Global radiation on the inclined plane [W/m²]

Bounding box:

List of Data Sources for Measurements

SwissMetNet – measurement network for Switzerland

Measurements interpolated from 160 stations run by MeteoSwiss.

Usage: &source=swissmetnet

Frequency: 1 hours

Temporal range: 1999-01-01 ... NOW +0 minutes

Available Parameters:

☀️ bh: Direct radiation on the horizontal plane [W/m²]
cdd: Cooling degree days [°C]
dd: Wind direction [°]
☀️ dh: Diffuse radiation on the horizontal plane [W/m²]
☀️ dni: Direct normal irradiation [W/m²]
☀️ e: Energy output per kWp installed [Wh/kWp]
☀️ eTotal: Total/effective energy output [kWh]
ff: Wind speed [km/h]
fx: Wind gusts [km/h]
gh: Global radiation (on the horizontal plane) [W/m²]
☀️ ghMax: Clear sky radiation [W/m²]
☀️ gk: Global radiation on the inclined plane [W/m²]
hdd: Heating degree days [°C]
qff: Mean sea level pressure [hPa]
rr: Precipitation rate [mm/h]
sy: Weather symbol [weather_symbol]
td: dew point temperature [°C]
tt: Air temperature [°C]

Bounding box(es):

SolarSat, satellite-based radiation data

SolarSat provides radiation data, independent of measurement instruments, for (almost) any location in the world.

Usage: &source=solarsat

Frequencies: 10 minutes , 15 minutes

Temporal range: 2018-01-01 ... NOW +0 minutes

Available Parameters:

☀️ bh: Direct radiation on the horizontal plane [W/m²]
☀️ dh: Diffuse radiation on the horizontal plane [W/m²]
☀️ dni: Direct normal irradiation [W/m²]
gh: Global radiation (on the horizontal plane) [W/m²]
☀️ ghMax: Clear sky radiation [W/m²]
☀️ gk: Global radiation on the inclined plane [W/m²]

Bounding box(es):

Precipitation radar, Switzerland

Near real-time precipitation data based on Swiss radar stations.

Usage: &source=radar-switzerland

Frequency: 5 minutes

Temporal range: NOW -30 days ... NOW +0 minutes

Available Parameters:

rr: Precipitation rate [mm/h]

Bounding box(es):

Contents

Getting Started

Tutorial for Solar ☀️ Applications

API Docs

/forecast and /measurements

Meta data (parameters, data sources)

List of Weather Parameters

List of Forecast Models

MOS MIX

Cosmo 1km, Switzerland

Global Forecast System

CloudMove nowcasting system

List of Data Sources for Measurements

SwissMetNet – measurement network for Switzerland

SolarSat, satellite-based radiation data

Precipitation radar, Switzerland