Rain in the last days

Configuration
1

Hi,
I use the OpenWeatherMap integration with hourly mode.

The integration exposes a rain sensor that, according to the documentation, it shows the “Rain volume for the last hour, mm.”

In a script I need a variable that represents the rain volume of the last X days, but I can’t figure out how to create it.

The bast would be to have the number of days as a parameter, but if it is not possible, a fixed value would be ok.

Can anybody help me?
Thank you
Matteo

1 Like
2

You can use variables in scripts that can be passed to the script when you call it:

You can use a loop to make a sum of all hourly values for the given days. The naming of the attributes in the OWM sensor should make this quite easy.

3

Hi Florian,
thank you for your reply.

I can’t find out how to get the “hourly values for the given days”.
The sensor.openweathermap_rain sensor just has the following attributes:

state_class: measurement
unit_of_measurement: mm
attribution: Data provided by OpenWeatherMap
friendly_name: OpenWeatherMap Rain

Matteo

4

Ah, you’re using the official integration. It doesn’t provide the necessary data.
I use this custom component:

5

Thank you,
it seems interesting :slight_smile:

But it tracks only the last 5 days :frowning: Why?!

6

Well, for irrigation purposes it doesn’t really matter how much it rained a whole week ago. Could also be that it’s an API limitation. @petergridge can surely answer that.

If you need more, you will have to do deal with that yourself. Maybe use the old values from the recorder in a statistic sensor. Or write the values periodically into variables or text inputs.

7

I found a solution using the Statistics integration.

First of all I created a template sensor, just to be sure to have the entity updated once a hour even if the value do not change (the update is due to the attribute):

template:
  - trigger:
      - platform: time_pattern
        minutes: "0" # every hour
    sensor:
      - name: "Rain last hour"
        state: "{{ states('sensor.openweathermap_rain') }}"
        unit_of_measurement: "ml"
        attributes:
          updated_at: "{{ now() }}"

Then I created the statistics sensors, to sum up the hour rain volumes:

sensor:
  - platform: statistics
    name: "Rain last day"
    entity_id: sensor.rain_last_hour
    state_characteristic: total
    max_age:
      hours: 24
    sampling_size: 24
    precision: 0
      
  - platform: statistics
    name: "Rain last 2 days"
    entity_id: sensor.rain_last_hour
    state_characteristic: total
    max_age:
      hours: 48
    sampling_size: 48
    precision: 0

Hope this can help :slight_smile:

6 Likes
8

Hi, the API only exposed the last 5 days data. You can find the documentation on the openweathermap site.

9

Are you still using this? I tried setting it up with the regular openweathermap integration in hourly mode, however i am getting values that are way too high.

10

Yes, still using it, even if the data is not too accurate. Probably, the only way to have accurate data is to have a weather station

13

so i got this to work

only to discover that openweathermap updates rain mm/h each 10 minutes

so i guess it has to update every 10 minutes and not at minute number 0

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image1634×445 14.7 KB

Here is how i ended up doing the same thing

in configuration.yaml

homeassistant:
  packages:
    sensor_rain: !include rainmeter.yaml
    sensor_rain_1h: !include rainmeter_1h.yaml
    sensor_rain_24h: !include rainmeter_24h.yaml
    sensor_rain_30d: !include rainmeter_30d.yaml

rainmeter.yaml

template:
  - trigger:
      - platform: state
        entity_id: sensor.openweathermap_rain
    sensor:
      - name: "rain last hour"
        state: "{{ states('sensor.openweathermap_rain') }}"
        unique_id: "rain_last_hour"
        unit_of_measurement: "mm"
        attributes:
          updated_at: "{{ now() }}"

that only updates when there are a change and not at fixed interval, i did it this way as who knows if openweathermap changes the interval

include rainmeter_1h.yaml

    sensor:
      - platform: statistics
        name: "Rain during the last hour"
        entity_id: sensor.rain_last_hour
        unique_id: "rain_last_1h"
        state_characteristic: total
        max_age:
          hours: 1
        precision: 0

rainmeter_24h.yaml

    sensor:
      - platform: statistics
        name: "Rain during the last 24 hours"
        entity_id: sensor.rain_last_hour
        unique_id: "rain_last_24h"
        state_characteristic: total
        max_age:
          hours: 24
        precision: 0

rainmeter_30d.yaml

    sensor:
      - platform: statistics
        name: "Rain during the last 30 days"
        entity_id: sensor.rain_last_hour
        unique_id: "rain_last_30d"
        state_characteristic: total
        max_age:
          days: 30
        precision: 0

and yeah, not the most precise way, but then as i write we have very slow rain and openweathermap says no rain

1 Like
14

I also receive values that are way too high, maybe 5-10 times more than forecasted.
I see that the Openweather sensor.openweathermap_rain it updates every 10 min, so for the newly created sensor “Rain last hour” I have divided it by 6.

template:

  • trigger:
    • platform: time_pattern
      minutes: “0” # every hour
      sensor:
    • name: “Rain last hour”
      state: “{{ states(‘sensor.openweathermap_rain’)| float(0) / 6 }}”
      unit_of_measurement: “mm”
      attributes:
      updated_at: “{{ now() }}”

The rain has stopped and i cannot verify, but the values are closer to reality. For example a 1mm/hr rain is a light rain (the car wiper blades can run intermittently), while a 10mm/hr (is more of a rain-storm where wiper blades might need a 3rd speed).