Extracting values from weather.forecast_home

Configuration
1

This must have been asked before, but my search skills have failed me.

Weather.home provides the following information:-

temperature: 6.5
temperature_unit: °C
humidity: 77
pressure: 990.2
pressure_unit: hPa
wind_bearing: 227.6
wind_speed: 13.3
wind_speed_unit: km/h
visibility_unit: km
precipitation_unit: mm
forecast:
  - condition: partlycloudy
    datetime: '2023-01-09T12:00:00+00:00'
    wind_bearing: 290.9
    temperature: 8.2
    templow: 4.6
    wind_speed: 33.1
    precipitation: 0
  - condition: rainy
    datetime: '2023-01-10T12:00:00+00:00'
    wind_bearing: 219.5
    temperature: 12.9
    templow: 4.9
    wind_speed: 30.2
    precipitation: 8.5
  - condition: rainy
    datetime: '2023-01-11T12:00:00+00:00'
    wind_bearing: 240
    temperature: 8.5
    templow: 6.8
    wind_speed: 31.7
    precipitation: 0.6
  - condition: rainy
    datetime: '2023-01-12T12:00:00+00:00'
    wind_bearing: 232.8
    temperature: 11.7
    templow: 8.4
    wind_speed: 29.9
    precipitation: 12.2
  - condition: cloudy
    datetime: '2023-01-13T12:00:00+00:00'
    wind_bearing: 242.4
    temperature: 10.1
    templow: 7.3
    wind_speed: 19.4
    precipitation: 0.4
attribution: >-
  Weather forecast from met.no, delivered by the Norwegian Meteorological
  Institute.
friendly_name: Forecast Home

Using states() and state_attr() I can easily get the top level attributes, but how would I get to the data in the forecast array.

When using (in dev tools):-

{{state_attr('weather.forecast_home','forecast')}}

returns a json array:-

[{'condition': 'partlycloudy', 'datetime': '2023-01-09T12:00:00+00:00', 'wind_bearing': 290.9, 'temperature': 8.2, 'templow': 4.6, 'wind_speed': 33.1, 'precipitation': 0.0}, {'condition': 'rainy', 'datetime': '2023-01-10T12:00:00+00:00', 'wind_bearing': 219.5, 'temperature': 12.9, 'templow': 4.9, 'wind_speed': 30.2, 'precipitation': 8.5}, {'condition': 'rainy', 'datetime': '2023-01-11T12:00:00+00:00', 'wind_bearing': 240.0, 'temperature': 8.5, 'templow': 6.8, 'wind_speed': 31.7, 'precipitation': 0.6}, {'condition': 'rainy', 'datetime': '2023-01-12T12:00:00+00:00', 'wind_bearing': 232.8, 'temperature': 11.7, 'templow': 8.4, 'wind_speed': 29.9, 'precipitation': 12.2}, {'condition': 'cloudy', 'datetime': '2023-01-13T12:00:00+00:00', 'wind_bearing': 242.4, 'temperature': 10.1, 'templow': 7.3, 'wind_speed': 19.4, 'precipitation': 0.4}]

So if I wanted to extract for example, the high and low temperature for the day, or if any of the forecast array elements contained rain ?

The idea is to extend my morning TTS to provide this information, which already does:-

Good Morning! The temperature is outside currently
{{state_attr('weather.forecast_home','temperature')}} degrees, and the
weather is forecast to be {{states('weather.forecast_home')}}
2

You are asking many different approaches so there will not be a single answer… can give you some of my stuff so you can think it over

-- max of various forecast values today
{{ (state_attr('weather.openweathermap', 'forecast')|selectattr('datetime', 'lt', (now().replace(hour=23,minute=59)).isoformat()))| map(attribute='temperature') | list | max }}
{{ ('temperature: -1.3 oc').split(': ',1)[1].split(' oc')[0] }}

-- value of weather attrib specific time
{% set tomorrow = (today_at('00:00') + timedelta(days=1)).strftime('%F') %}
{{ weather | selectattr('datetime', 'match', '^'~tomorrow) | selectattr('datetime', 'match', '^.*0(3|6):00') | map(attribute='precipitation_probability') | list }}

{{ (state_attr('weather.home', 'forecast')|selectattr('datetime', 'eq', (today_at('5:00').astimezone(utcnow().tzinfo) + timedelta (days=1)).isoformat())|list|first).temperature }}
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3

Here is an example of extracting it from the hourly data. Since the hourly data can span days, and I want the max / min for today. The first clause extract elements for todays date.


sensor:
  - platform: template
    sensors:
      weather_forecast_high:
        unit_of_measurement: "°F"
        value_template: >-
          {{ state_attr('weather.home_hourly','forecast') |
             selectattr('datetime', 'search', now().timestamp() | timestamp_custom('%Y-%m-%d')) | 
             map(attribute='temperature') | max
          }}
        device_class: temperature
      weather_forecast_low:
        unit_of_measurement: "°F"
        value_template: >-
          {{ state_attr('weather.home_hourly','forecast') |
             selectattr('datetime', 'search', now().timestamp() | timestamp_custom('%Y-%m-%d')) | 
             map(attribute='temperature') | min
          }}
        device_class: temperature
      weather_current_condition:
        value_template: >-
          {{ state_attr('weather.home_hourly','forecast') |
             selectattr('datetime', 'search', now().timestamp() | timestamp_custom('%Y-%m-%d')) | 
             map(attribute='condition') | first
          }}
4

Thanks both.

I’m familiar with using split to break apart strings, I was wondering if there was a more elegant way given its json.

Map however is new to me (as is most jinja2 stuff!), which looks interesting.

5

ok map and selectattr are seriously useful. I didn’t expect to get the answer for whether its going to rain or not today so easily:-

{% set will_rain = state_attr('weather.forecast_home','forecast') | selectattr('condition','equalto','rainy') | map(attribute='condition') | first
%}

{{will_rain}}

The only issue I have is that if the json array doesn’t contain the word ‘rainy’, I get this error:-

UndefinedError: No first item, sequence was empty.

How would I go about handling that exception ? Basically I want will_rain to be true if the word rainy is in that json array, or false if not.

6

That is an excellent question. I do not know. Hopefully someone does. I have the same problem when the hourly forecast no longer contains data for today and it Is still today (11 pm).

7

I’m not sure if jinaj2 has proper exception handling, but I managed to get around the issue like so:-

set will_it_rain = state_attr('weather.forecast_home','forecast') | selectattr('condition','equalto','rainy') | list
%}
{% if will_it_rain  is defined and will_it_rain %}
It will rain
{% else %}
No Rain
{%endif%}
2 Likes
8

This is my current final version using @PeteRage script heavily as the basis, with some additional if statements to avoid when no data is avaialable.

I use this as part of a google TTS speech in the morning:-

      msg: >-
        Good Morning! The temperature outside is currently
        {{state_attr('weather.forecast_home_hourly','temperature')}} degrees, 
        {%set highof = state_attr('weather.forecast_home_hourly','forecast') |      
        selectattr('datetime', 'search', now().timestamp() | timestamp_custom('%Y-%m-%d')) | map(attribute='temperature') | max %}
        {% if highof is defined and highof %}
        with a high of {{highof}} degrees
        {%endif%}
        {%set lowof = state_attr('weather.forecast_home_hourly','forecast') |   
        selectattr('datetime', 'search', now().timestamp() | timestamp_custom('%Y-%m-%d')) | map(attribute='temperature') | min %}
        {% if lowof is defined and lowof %}
        with a low of {{lowof}}
        {%endif%}
        .The weather is forecast to be
        {{states('weather.forecast_home_hourly')}} 
        {%set check_for_rain = state_attr('weather.forecast_home_hourly','forecast') |
        selectattr('datetime', 'search', now().timestamp() | timestamp_custom('%Y-%m-%d')) | selectattr('condition','equalto','rainy') | list%}
        {% if check_for_rain is defined and check_for_rain %} and rainy. {% else %} with no rain.
        {%endif%}The house is currently
        {{state_attr('climate.main_house','current_temperature')}} degrees.
3 Likes
9

You can access any value by using


{{ state_attr('weather.forecast_home','forecast')[0]['templow'] }}

where [0] represents the first list entry.

7 Likes
10

how do I use this code?

11

You don’t. The weather integration has changed and the earlier posts no longer apply.

Read all of this:

and if you still need help, start a new topic explaining which weather integration you’re using and what you’re trying to achieve.

2 Likes