This endpoint provides Population Weighted Heating Degree Days (HDD) for all 50 US states, using all available forecast hours. HDD measures how cold a day is relative to a 65°F base, weighted by population density to better reflect energy demand.
Choose a supported forecast model using the dropdown. The model is part of the URL path; initialization_time remains an optional query parameter. Results come from the latest completed degree-day calculation for that model when no initialization time is specified.
| Name | Description | Format |
|---|---|---|
| initialization_time optional | The initialization time for the forecast. Uses only date, hour and minutes. Seconds are discarded. | YYYY-MM-DDThh:mm:ssZ |
| Name | Description | Format |
|---|---|---|
| initialization_time optional | The initialization time for the forecast. Uses only date, hour and minutes. Seconds are discarded. | YYYY-MM-DDThh:mm:ssZ |
| Name | Description | Format |
|---|---|---|
| initialization_time optional | The initialization time for the forecast. Uses only date, hour and minutes. Seconds are discarded. | YYYY-MM-DDThh:mm:ssZ |
| Name | Description | Format |
|---|---|---|
| initialization_time optional | The initialization time for the forecast. Uses only date, hour and minutes. Seconds are discarded. | YYYY-MM-DDThh:mm:ssZ |
| Name | Description | Format |
|---|---|---|
| initialization_time optional | The initialization time for the forecast. Uses only date, hour and minutes. Seconds are discarded. | YYYY-MM-DDThh:mm:ssZ |
| Name | Description | Format |
|---|---|---|
| initialization_time optional | The initialization time for the forecast. Uses only date, hour and minutes. Seconds are discarded. | YYYY-MM-DDThh:mm:ssZ |
| Name | Description | Format |
|---|---|---|
| initialization_time optional | The initialization time for the forecast. Uses only date, hour and minutes. Seconds are discarded. | YYYY-MM-DDThh:mm:ssZ |
| Name | Description | Format |
|---|---|---|
| initialization_time optional | The initialization time for the forecast. Uses only date, hour and minutes. Seconds are discarded. | YYYY-MM-DDThh:mm:ssZ |
| Name | Description |
|---|---|
| initialization_time optional | An ISO 8601 date string representing the time at which the forecast was made. Supports YYYY-MM-DDThh:mm:ssZ. Uses only date, hour and minutes. Seconds are discarded. |
| -m --model | Set to ecmwf-det . |
| -o, --output Optional | Output file path. Supports .csv and .json. If omitted, prints to console. |
| Name | Description |
|---|---|
| initialization_time optional | The initialization time for the forecast. Formats: YYYYMMDDHH, YYYY-MM-DDTHH, YYYY-MM-DDTHH:mm:ss. |
| -m --model | Set to ecmwf-ens . |
| -o, --output Optional | Output file path. Supports .csv and .json. |
| Name | Description |
|---|---|
| initialization_time optional | The initialization time for the forecast. |
| -m --model | Set to aifs . |
| -o, --output Optional | Output file path. Supports .csv and .json. |
| Name | Description |
|---|---|
| initialization_time optional | The initialization time for the forecast. |
| -m --model | Set to gfs . |
| -o, --output Optional | Output file path. Supports .csv and .json. |
| Name | Description |
|---|---|
| initialization_time optional | The initialization time for the forecast. |
| -m --model | Set to wm-6 . |
| -o, --output Optional | Output file path. Supports .csv and .json. |
| Name | Description |
|---|---|
| initialization_time optional | The initialization time for the forecast. |
| -m --model | Set to wm-6-3km . |
| -o, --output Optional | Output file path. Supports .csv and .json. |
| Name | Description |
|---|---|
| initialization_time optional | The initialization time for the forecast. |
| -m --model | Set to wm-4.5-ens-mean . |
| -o, --output Optional | Output file path. Supports .csv and .json. |
| Name | Description |
|---|---|
| initialization_time optional | The initialization time for the forecast. |
| -m --model | Set to gefs . |
| -o, --output Optional | Output file path. Supports .csv and .json. |
| Name | Type | Description |
|---|---|---|
| initialization_time optional | str | The initialization time for the forecast. |
| model | str | Set to ecmwf-det . |
| output_file Optional | str | Path to save the response data. Supports .csv and .json. |
| print_response Optional | bool | Whether to print the response data to console. Defaults to False. |
| Name | Type | Description |
|---|---|---|
| initialization_time optional | str | The initialization time for the forecast. |
| model | str | Set to ecmwf-ens . |
| output_file Optional | str | Path to save the response data. Supports .csv and .json. |
| print_response Optional | bool | Whether to print the response data to console. Defaults to False. |
| Name | Type | Description |
|---|---|---|
| initialization_time optional | str | The initialization time for the forecast. |
| model | str | Set to aifs . |
| output_file Optional | str | Path to save the response data. Supports .csv and .json. |
| print_response Optional | bool | Whether to print the response data to console. Defaults to False. |
| Name | Type | Description |
|---|---|---|
| initialization_time optional | str | The initialization time for the forecast. |
| model | str | Set to gfs . |
| output_file Optional | str | Path to save the response data. Supports .csv and .json. |
| print_response Optional | bool | Whether to print the response data to console. Defaults to False. |
| Name | Type | Description |
|---|---|---|
| initialization_time optional | str | The initialization time for the forecast. |
| model | str | Set to wm-6 . |
| output_file Optional | str | Path to save the response data. Supports .csv and .json. |
| print_response Optional | bool | Whether to print the response data to console. Defaults to False. |
| Name | Type | Description |
|---|---|---|
| initialization_time optional | str | The initialization time for the forecast. |
| model | str | Set to wm-6-3km . |
| output_file Optional | str | Path to save the response data. Supports .csv and .json. |
| print_response Optional | bool | Whether to print the response data to console. Defaults to False. |
| Name | Type | Description |
|---|---|---|
| initialization_time optional | str | The initialization time for the forecast. |
| model | str | Set to wm-4.5-ens-mean . |
| output_file Optional | str | Path to save the response data. Supports .csv and .json. |
| print_response Optional | bool | Whether to print the response data to console. Defaults to False. |
| Name | Type | Description |
|---|---|---|
| initialization_time optional | str | The initialization time for the forecast. |
| model | str | Set to gefs . |
| output_file Optional | str | Path to save the response data. Supports .csv and .json. |
| print_response Optional | bool | Whether to print the response data to console. Defaults to False. |
Returns population weighted heating-degree-days (HDD) data for all 50 US states and the list of forecast dates.
| Name | Description | Format |
|---|---|---|
| hdd | HDD values keyed by forecast date_string; each date maps to a state-to-value object | object |
| date_string | Object keyed by state_name with HDD values for that date | object |
| state_name | HDD value for the given state on that date_string | floating point number |
| dates | Array of forecast dates in YYYY-MM-DD format | YYYY-MM-DD |
| date | Forecast date in YYYY-MM-DD format | - |