Hourly Weather Variables
Settings
Celsius °C
Fahrenheit °F
Temperature Unit
Km/h
m/s
Mph
Knots
Wind Speed Unit
Millimeter
Inch
Precipitation Unit
ISO 8601 (e.g. 2021-01-01)
Unix timestamp
Timeformat
Preview
API Documentation
The API endpoint /v1/ecmwf accepts a WGS4 coordinate, a list of weather variables and responds with a JSON hourly weather forecast for 7 days. Time always starts at 0:00 today and contains 168 hours. All URL parameters are listed below:
Parameter
Format
Required
Default
Description
latitude, longitude
Floating point
Yes
Geographical WGS84 coordinate of the location
hourly
String array
No
A list of weather variables which should be returned. Values can be coma separated, or multiple &hourly= parameter in the URL can be used.
temperature_unit
String
No
celsius
If fahrenheit is set, all temperature values are converted to Fahrenheit.
windspeed_unit
String
No
kmh
Other wind speed speed units: ms , mph and kn
precipitation_unit
String
No
mm
Other precipitation amount units: inch
timeformat
String
No
iso8601
If format unixtime is selected, all time values are returned in UNIX epoch time in seconds. Please not that all time is then in UTC! For daily values with unix timestamp, please apply utc_offset_seconds again to get the correct date.
past_days
Integer (0-2)
No
0
If past_days is set, yesterdays or the day before yesterdays data are also returned.
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 and average or sum.
Variable
Valid time
Unit
Description
pressure_msl surface_air_pressure
Instant
hPa
Atmospheric air pressure reduced to sea level (Mean sea level) and actual pressure at surface level
skin_temperature
Instant
°C (°F)
Temperature of the the surface. Depending on the type of surface (e.g. concrete) this temperature can be significantly higher then the 2 meter air temperature
soil_temperature_0_7cm
Instant
°C (°F)
Average temperature of the first soil level 0-7 cm below ground.
total_column_integrated_water_vapour
Instant
kg/m²
Total amount of water in the atmosphere.
temperature_2m temperature_1000hPa, ...
Instant
°C (°F)
Air temperature 2 meter above ground. Additional temperature in the atmopshere are given on different pressure levels.
geopotential_height_1000hPa
Instant
gpm
Geopotential height on different atmospherc pressure levels
windspeed_10m
Instant
gpm
Geopotential height on different atmospherc pressure levels
windspeed_10m windspeed_1000hPa, ...
Instant
km/h (mph, m/s, knots)
Wind speed at 10 meters above ground. Wind speed on 10 meters is the standard level. Additional wind speeds are given on atmospheric pressure levels.
winddirection_10m winddirection_1000hPa, ...
Instant
°
Wind direction at 10 meters above ground and different pressure levels.
relativehumidity_2m relative_humidity_1000hPa, ...
Instant
%
Relative humidity at 2 meters above ground and atmospherc pressure levels
specific_humidity_1000hPa, ...
Instant
g/kg
Specific humidity at different atmospherc pressure levels
atmosphere_relative_vorticity_1000hPa, ...
Instant
s⁻¹
Relative vorticity at different atmospherc pressure levels
divergence_of_wind, ...
Instant
s⁻¹
Differgence of wind at different atmospherc pressure levels
JSON Return Object
On success a JSON object will be returned.
{
"latitude": 52.52,
"longitude": 13.419,
"generationtime_ms": 2.2119,
"hourly": {
"time": ["2021-08-28T00:00", "2021-08-28T01:00", "2021-08-28T02:00", ...],
"temperature_2m": [13, 12.7, 12.7, 12.5, 12.5, 12.8, 13, 12.9, 13.3, ...]
},
"hourly_units": {
"temperature_2m": "°C"
},
}
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 up to 5 km away.
generationtime_ms
Floating point
Generation time of the weather forecast in milli seconds. This is mainly used for performance monitoring and improvements.
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"
}
This service is based on data and products of the European Centre for Medium-Range Weather Forecasts (ECMWF). Source www.ecmwf.int. ECMWF does not accept any liability whatsoever for any error or omission in the data, their availability, or for any loss or damage arising from their use.