So I could use the following:
weather.home //sunny
value_template: "{{ state_attr('weather.home', 'temperature') } //temperature
value_template: "{{ state_attr('weather.home', 'forecast[0].temperature') } //forecast TOMORROW
Unfortunately the 1st entry in forecast is never for today, but only starting from next day. Any chance I could also add the current day here?
It looks like they only have daily forecast. I use openweathermap which should give you want you want.
EDIT
Actually, doesn’t look like they do 12pm, every 3 hours so they jump from 11am to 2pm.
You can check out others here:
Unfortunately openweathermap does not offer the daily forecast in the free plan. I would mostly be interested in daily.temperature.max or something like that. Is there any HA weather integration that offers this?
I also found the default 5-day-3-hour forecast is very very bad for my location. Eg for this midnight, it shows 16°C, whereas current nights are never > 10° and any local forecasts confirm that’s below. So anyways I cannot use openweathermap for my case…
For now I solved it as follows: using yr.no with a 4h weather forecast, and evaluation my conditions at 10am in the automation. Then I will receive the temperature approx at the hottest time of the day (2pm). And if threshold is exceeded, I close my blinders.
- name: weather_forecast
platform: yr
forecast: 4
scan_interval: 600
monitored_conditions:
- temperature
- cloudiness
No they don’t, but I use sensors to pull that information from here:
I created a day min and max sensor with OWM like this (details in the thread mentioned above):
# Day min and max temp
- platform: template
sensors:
day_max_temp:
friendly_name: "24 Std. Höchsttemperatur"
unit_of_measurement: "°C"
entity_id: weather.openweathermap
value_template: >
{#% set start = (now().replace(hour=0,minute=0,second=0).timestamp() * 1000) | int %#}
{% set start = (now().timestamp() * 1000) | int %}
{% set end = start + 86400000 %}
{{ state_attr('weather.openweathermap', 'forecast') | selectattr('datetime', '>=', start) | selectattr('datetime','<=', end) | map(attribute='temperature') | list | max }}
day_min_temp:
friendly_name: "24 Std. Tiefsttemperatur"
unit_of_measurement: "°C"
entity_id: weather.openweathermap
value_template: >
{#% set start = (now().replace(hour=0,minute=0,second=0).timestamp() * 1000) | int %#}
{% set start = (now().timestamp() * 1000) | int %}
{% set end = start + 86400000 %}
{{ state_attr('weather.openweathermap', 'forecast') | selectattr('datetime', '>=', start) | selectattr('datetime','<=', end) | map(attribute='temperature') | list | min }}
Then you can use an automation like this:
- alias: 'Sun protection on sunny days'
trigger:
- platform: time
at: '09:00:00'
condition:
condition: and
conditions:
- condition: numeric_state
entity_id: sensor.day_max_temp
above: 20.0
- condition: numeric_state
entity_id: sensor.owm_cloud_coverage
below: 50
action:
- service: notify.telegram
data:
message: "Sonnenschutz \U0001F525"
- service: script.alle_halb_geschlossen
Enjoy!
Which mode did you chose? Did you stick to the default hourly?
Just for reference: I’m not satisfied with the default OWM implementation in HA. Especially as owm provides a daily report that directly gives out the min/max temperatures for a day. So no need for calculations.
I set up my own sensors using a rest_template as follows:
- name: owm_report
platform: rest
resource: 'https://api.openweathermap.org/data/2.5/onecall?units=metric&exclude=minutely,hourly&lat=<lat>&lon=<lon>&appid=<apikey>'
scan_interval: 600
value_template: '{{ value_json.current.temp }}'
unit_of_measurement: '°C'
json_attributes_path: "$.daily[0]"
json_attributes:
- temp
- clouds
- platform: template
sensors:
weather_today_max_temp:
friendly_name: 'Today Max Temp'
device_class: temperature
unit_of_measurement: '°C'
value_template: '{{ state_attr("sensor.owm_report", "temp")["max"] }}'
weather_today_min_temp:
friendly_name: 'Today Min Temp'
device_class: temperature
unit_of_measurement: '°C'
value_template: '{{ state_attr("sensor.owm_report", "temp")["min"] }}'
weather_today_clouds:
friendly_name: 'Today Cloudiness'
unit_of_measurement: '%'
value_template: '{{ state_attr("sensor.owm_report", "clouds") }}'
Much better! Thx a lot!
Maybe it would make sense to ask the maintainer of the OWM platform to include this within the official platform? 
PS: The OWM One Call API is being implemented (Convert OpenweatherMap Integration to use "one-call-api"). So just be patient… 
I like your solution, but I am a bit confused since temp and temp_min/temp_max are always the same in my installation. Now I found this in the OWM API docs:
Please, do not confuse min/max parameters in our weather APIs.
In Current weather API , Hourly forecast API and 5 day / 3 hour forecast API - temp_min and temp_max are optional parameters mean min / max temperature in the city at the current moment just for your reference. For large cities and megalopolises geographically expanded it might be applicable. In most cases both temp_min and temp_max parameters have the same volume as ‘temp’. Please, use temp_min and temp_max parameters in current weather API optionally.
At least for the free subscription plan this might not be what you want?!
PS: Sorry, my mistake. You are using the new One Call API which indeed does provide day min/max temp (daily.temp.min).
Thanks for your feedback.
So we can hope to switch back to the owm plugin in some weeks?
Hi, many thanks for the code. It´s generally working. Now I have two requests.
https://api.openweathermap.org/data/2.5/onecall?units=metric&exclude=minutely,hourly&lat=<lat>&lon=<lon>&appid=!secrets=myapikey
I did not move the apikey/appid to secrets. Because, if anybody would get knowledge of it, I don’t care. It’s a free service with no personal information.
If you want it in secrets, you have to move the full url to secrets, and then use resource: !secret openweatherurl
Like this solution. Basic question, the I assume need to be replaced by actual values or are these subsituted by HA? If so: where does the apikey come from?
This works great! Thanks.
Please forgive my question I am a HA beginner, but how do I integrate your template?
First part in the configuration.yaml and the second as manual automation? 
Hi
IMHO you don’t need the template anymore since the OWM integration uses OWM one call API to provide forecast information directly:
https://openweathermap.org/api/one-call-api
Therefore, you can just write something like this in your automations:
conditions:
- condition: numeric_state
entity_id: sensor.openweathermap_forecast_temperature
above: 20.0
The only thing that may be missing is a cloud coverage forecast. But there is a current cloud coverage sensor (sensor.openweathermap_cloud_coverage).
HTH
Thorsten
If it helps, here’s how I did it:
First, I have a sensor collecting forecasted temperature 1 day from now:
# Buienradar weather data
# https://www.home-assistant.io/integrations/sensor.buienradar/
- platform: buienradar
monitored_conditions:
- temperature_1d
From what I saw, this sensor switches max forecasted temperature around 2am at night.
So I implemented a SQL sensor that queries the max forecasted temperature between current time yesterday and last midnight
(I record my data in a local MariaDB)
# Determine max forecasted temperature for 'today'
- platform: sql
db_url: !secret mariadb_url
queries:
- name: max_temp_fcst_today
query: >
SELECT date(date_add(last_updated, INTERVAL 1 DAY)) AS date, MAX(state) AS max_temp
FROM home_assistant.states
WHERE entity_id = 'sensor.br_temperature_1d'
AND last_updated BETWEEN DATE_ADD(NOW(), INTERVAL -1 DAY) AND CURDATE();
column: max_temp
unit_of_measurement: °C
In other words: I went back into my history to retrieve the forecasted temperature, rather than trying to collect a forecasted temperature for today when I need it.
Another approach if you’re not comfortable with writing SQL statements would be to use an automation that writes the state or attribute of a (sensor) entity into an input_number entity at a given point of time. You can then use this over a certain interval while the source changes.