Yearly Accumulated Day Counts

These parameters represent the number of days that fulfil a certain condition since the 1^st of January of the queried year.

Temperature Dependent | Precipitation Dependent

Temperature Dependent

Below is an overview of all temperature dependent parameters:

Every parameter is now explained in more detail:

Vegetation Days

This parameter returns the number of vegetation days (days on which the mean temperature was above 5°C) since the 1^st of January.

vegetation_days:d

Examples

Show the number of vegetation days for 35 days after the 10^th of February.

https://api.meteomatics.com/2025-04-03T00:00:00ZP35D:P1D/vegetation_days:d/47.412164,9.340652/html

To obtain the data in a different output format, just replace the format parameter in the URL by one of the following: csv, json, xml, png, html, netcdf.
Here is an example for the json format:

https://api.meteomatics.com/2025-04-03T00:00:00ZP10D:P1D/vegetation_days:d/47.412164,9.340652/json

{"version":"3.0","user":"api-test","dateGenerated":"2017-08-25T08:38:48Z","status":"OK","data":
[{"parameter":"vegetation_days:d","coordinates":[{"lat":47.4122,"lon":9.34065,"dates":
[{"date":"2017-03-10T00:00:00Z","value":11},{"date":"2017-03-11T00:00:00Z","value":12},
{"date":"2017-03-12T00:00:00Z","value":13},{"date":"2017-03-13T00:00:00Z","value":14},
{"date":"2017-03-14T00:00:00Z","value":15},{"date":"2017-03-15T00:00:00Z","value":16},
{"date":"2017-03-16T00:00:00Z","value":17},{"date":"2017-03-17T00:00:00Z","value":18}]}]}]}

Heating Days

This parameter returns the number of heating days (days for which the 24h-mean is less than 15°C, or the number of days buildings need to be heated) since the 1^st of January.

heating_days:d

Show the heating days for the 35 days after the 10^th of May.

https://api.meteomatics.com/2025-04-03T00:00:00ZP35D:P1D/heating_days:d/47.412164,9.340652/html

Heating Degree Days

Heating degree days (HDD) is a measurement designed to quantify the energy demand for heating a building. This parameter returns the accumulated difference in °C between the daily mean temperature and a configurable base temperature, if the daily mean temperature is below that base temperature, since the 1^st of January or on a daily base (daily heating degree days).

heating_degree_days:hdd

heating_degree_days_base_<base_temperature>:hdd

daily_heating_degree_days:hdd

daily_heating_degree_days_base_<base_temperature>:hdd

Available base temperatures: continuous from 0°C to 30°C. The base temperature should be in °C but without using the unit itself in the query.
The default is 15°C.

Show the heating degree days and the daily heating degree days for 10 days after the 1^st of January with different base temperatures in Paris
https://api.meteomatics.com/2023-01-01T00Z--2023-01-10T00Z:PT24H/daily_heating_degree_days:hdd,daily_heating_degree_days_base_20:hdd,heating_degree_days:hdd,heating_degree_days_base_20:hdd/48.862439,2.346002/html
The following csv output shows the HDD with a base temperature of 16°C over three days in St. Gallen.
https://api.meteomatics.com/2025-04-03T00:00:00ZP3D:P1D/heating_degree_days_base_16:hdd,t_mean_2m_24h:C/47.412164,9.340652/csv
```
validdate;heating_degree_days_base_16:hdd;t_mean_2m_24h:C
2018-01-15T00:00:00Z;159.5;-1
2018-01-16T00:00:00Z;172.6;2.3
2018-01-17T00:00:00Z;184.3;4.2
2018-01-18T00:00:00Z;200.5;0.1
```

Cooling Degree Days

Cooling degree day (CDD) is a measurement designed to quantify the energy demand for cooling a building. This parameter returns the accumulated difference in °C between the daily mean temperature and a configurable base temperature, if the daily mean temperature is above that base temperature, since the 1^st of January or on a daily base.

cooling_degree_days:cdd

cooling_degree_days_base_<base_temperature>:cdd

daily_cooling_degree_days:cdd

daily_cooling_degree_days_base_<base_temperature>:cdd

Available base temperatures: continuous from 0°C to 30°C.
The default is 15°C.

Show the cooling degree days from the 1^st of June for a period of 10 days with different base temperatures in Paris
https://api.meteomatics.com/2023-06-01T00Z--2023-06-10T00Z:PT24H/daily_cooling_degree_days:cdd,daily_cooling_degree_days_base_20:cdd,cooling_degree_days:cdd,cooling_degree_days_base_20:cdd/48.862439,2.346002/html
The following csv output shows the CDD with a base temperature of 16°C over three days in St. Gallen.
https://api.meteomatics.com/2025-04-03T00:00:00ZP3D:P1D/cooling_degree_days_base_16:cdd,t_mean_2m_24h:C/47.412164,9.340652/csv
```
validdate;cooling_degree_days_base_16:cdd;t_mean_2m_24h:C
2021-07-01T00:00:00Z;65.8;13.9
2021-07-02T00:00:00Z;65.8;14.3
2021-07-03T00:00:00Z;65.8;15.8
2021-07-04T00:00:00Z;67.5;17.4
```

Desert Days / Extremely Hot Days

This parameter returns the number of extremely hot days (days on which the maximum temperature at 2m exceeds 35°C) since the 1^st of January.

desert_days:d

Examples

Show the number of desert days from the 10^th of April on for a period of 35 days. The plot below is generated for the coordinates 27°24'43.8"N 9°20'26.4"E, which is in Algeria close to the Libyan border.

https://api.meteomatics.com/2025-04-03T00:00:00ZP35D:P1D/desert_days:d/27.412164,9.340652/html

Hot Days

This parameter returns the number of hot days (days for which the 24-hour maximum temperature was greater than 30°C) since the 1^st of January.

hot_days:d

Examples

Show the number of hot days from the 10^th of April on for a period of 35 days. The plot below is generated for the coordinates 27°24'43.8"N 9°20'26.4"E, which is in Algeria close to the Libyan border.

https://api.meteomatics.com/2025-04-03T00:00:00ZP35D:P1D/hot_days:d/27.412164,9.340652/html

https://api.meteomatics.com/2025-04-03T00:00:00ZP35D:P1D/hot_days:d/27.412164,9.340652/csv

validdate;hot_days:d
2017-04-30T00:00:00Z;23
2017-05-01T00:00:00Z;24
2017-05-02T00:00:00Z;25
2017-05-03T00:00:00Z;26
2017-05-04T00:00:00Z;27
2017-05-05T00:00:00Z;28
2017-05-06T00:00:00Z;29
2017-05-07T00:00:00Z;30

Summer Days

This parameter returns the number of summer days (days for which the 24-hour maximum temperature was greater than 25°C) since the 1^st of January.

summer_days:d

Examples

Show the number of hot days from the 10^th of April on for a period of 35 days. The plot below is generated for the coordinates 27°24'43.8"N 9°20'26.4"E, which is in Algeria close to the Libyan border.

https://api.meteomatics.com/2025-04-03T00:00:00ZP35D:P1D/summer_days:d/27.412164,9.340652/html

Tropical Nights

This parameter returns the number of tropical nights (days for which the 24-hour minimum temperature was greater than 20°C) since the 1^st of January.

tropical_nights:d

Examples

Show the number of hot days from the 10^th of April on for a period of 35 days. The plot below is generated for the coordinates 27°24'43.8"N 9°20'26.4"E, which is in Algeria close to the Libyan border.

https://api.meteomatics.com/2025-04-03T00:00:00ZP35D:P1D/tropical_nights:d/27.412164,9.340652/html

Frost Days

This parameter indicates the count of frost days, which are days when the temperature fell below 0 degrees Celsius, since the 1st of January. The count of frost days corresponds to the count of freezing days in the United States.

frost_days:d

Examples

Show the number of frost days from the 10^th of January on for a period of 35 days.

https://api.meteomatics.com/2025-04-03T00:00:00ZP35D:P1D/frost_days:d/47.412164,9.340652/html

Show the number of frost days from the 10^th of April on for a period of 15 days.

https://api.meteomatics.com/2025-04-03T00:00:00ZP15D:P1D/frost_days:d/47.412164,9.340652/json

{"version":"3.0","user":"api-test","dateGenerated":"2018-02-14T15:53:19Z","status":"OK","data":
[{"parameter":"frost_days:d","coordinates":[{"lat":47.4122,"lon":9.34065,"dates":
[{"date":"2017-04-10T00:00:00Z","value":31},{"date":"2017-04-11T00:00:00Z","value":31},
{"date":"2017-04-12T00:00:00Z","value":31},{"date":"2017-04-13T00:00:00Z","value":31},
{"date":"2017-04-14T00:00:00Z","value":31},{"date":"2017-04-15T00:00:00Z","value":31},
{"date":"2017-04-16T00:00:00Z","value":31},{"date":"2017-04-17T00:00:00Z","value":31},
{"date":"2017-04-18T00:00:00Z","value":31},{"date":"2017-04-19T00:00:00Z","value":31},
{"date":"2017-04-20T00:00:00Z","value":32},{"date":"2017-04-21T00:00:00Z","value":33},
{"date":"2017-04-22T00:00:00Z","value":33},{"date":"2017-04-23T00:00:00Z","value":33},
{"date":"2017-04-24T00:00:00Z","value":33},{"date":"2017-04-25T00:00:00Z","value":33}]}]}]}

Ice Days

This parameter returns the number of ice days (days for which the 24-hour maximum temperature was less than 0°C) since 1st of January.

ice_days:d

Examples

Show the number of ice days from the 10^th of January on for a period of 35 days.

https://api.meteomatics.com/2025-04-03T00:00:00ZP35D:P1D/ice_days:d/47.412164,9.340652/html

Precipitation Dependent

Below is an overview of all precipitation dependent parameters:

Rain Days | Heavy Rain Days | Dry Days

Every parameter is now explained in more detail:

Rain Days

This parameter returns the number of rain days (days on which at least 0.1 mm of rain fell) since 1st of January.

rain_days:d

Examples

Show the number of rain days from the 10^th of April on for a period of 35 days.

https://api.meteomatics.com/2025-04-03T00:00:00ZP35D:P1D/rain_days:d/47.412164,9.340652/html

A part of the corresponding csv file.

https://api.meteomatics.com/2025-04-03T00:00:00ZP35D:P1D/rain_days:d/47.412164,9.340652/csv

validdate;rain_days:d
2017-04-30T00:00:00Z;57
2017-05-01T00:00:00Z;57
2017-05-02T00:00:00Z;58
2017-05-03T00:00:00Z;59
2017-05-04T00:00:00Z;60
2017-05-05T00:00:00Z;61
2017-05-06T00:00:00Z;61
2017-05-07T00:00:00Z;62

Heavy Rain Days

heavy_rain_days:d

This parameter returns the number of heavy rain days (days for which the precipitation sum was greater than 10mm) since 1st of January.

Examples

Show the number of heavy rain days from the 10^th of April on for a period of 35 days.

https://api.meteomatics.com/2025-04-03T00:00:00ZP35D:P1D/heavy_rain_days:d/47.412164,9.340652/html

Dry Days

This parameter returns the number of dry days since 1st of January.

dry_days:d

Examples

Show the number of dry days from the 10^th of April on for a period of 35 days.

https://api.meteomatics.com/2025-04-03T00:00:00ZP35D:P1D/dry_days:d/47.412164,9.340652/html

The corresponding data as a json output, for a period of 5 days.

https://api.meteomatics.com/2025-04-03T00:00:00ZP5D:P1D/dry_days:d/47.412164,9.340652/json

{"version":"3.0","user":"api-test","dateGenerated":"2018-02-28T10:57:47Z","status":"OK","data":
[{"parameter":"dry_days:d","coordinates":[{"lat":47.4122,"lon":9.34065,"dates":
[{"date":"2017-04-10T00:00:00Z","value":38},{"date":"2017-04-11T00:00:00Z","value":39},
{"date":"2017-04-12T00:00:00Z","value":40},{"date":"2017-04-13T00:00:00Z","value":41},
{"date":"2017-04-14T00:00:00Z","value":42},{"date":"2017-04-15T00:00:00Z","value":43}]}]}]}