Buienradar Rain 1d

Spiffo · May 23, 2025, 10:26am

QQ for verification: Buienradar has very many sensors, but I am interested in these:

Rain 1d, Rain 2d, Rain 3d, Rain 4d, Rain 5d

Are these backward looking? Meaning do they tell how much rain fell yesterday, day before yesterday, etc?

Looking to this to maybe assist me in determining whether to turn on sprinklers

Julius_Caesar · May 23, 2025, 11:01am

According to the documentation these look forward. For backward values you can use the history of the Rain last 24h

Spiffo · May 23, 2025, 3:37pm

Thanks, your empirical highness!

So this is a running total…

If I would like to 1) check every day at 20:00 (irrigation after dark, but to be decided when I’m still awake), what the 2) total rain was for the last 5 days. Preferably not by using an automation but by some sort of statistics sensor?

Sir_Goodenough · May 23, 2025, 8:34pm

Hello Spiffo,

Personally, I look at yesterdays rain by storing the value in a helper just before midnight, then use that to vary the amount of time the sprinkler is on the next day. The compensation Integration calculates the number based on my parameters.
This is the 3 chunks of code for that:

github.com/SirGoodenough/Home-Assistant-Config

automation2/Outside_A2.yaml

283511cb4


      
              - trigger: numeric_state
                entity_id: sensor.gw2000b_v2_2_4_lightning_strike_distance
                below: 9
                above: 0
            actions:
              - alias: "Announce the alert"
                action: script.tts_say_lightning
              - alias: "Hold so that we don't have repeated notifications"
                delay: 00:27:49
          
          - id: "1716577118814"
            alias: Set Sprinkler Runtime
            description: Get the compensation value from the data to set the runtime
            triggers:
              - trigger: time
                at: "23:59:59"
            conditions:
            actions:
              - action: input_number.set_value
                metadata: {}
                data:

github.com/SirGoodenough/Home-Assistant-Config

automation2/Outside_A2.yaml

283511cb4


      
            actions:
              - action: input_number.set_value
                metadata: {}
                data:
                  value: "{{ comp_sensor }}"
                target:
                  entity_id: input_number.sprinkler_time
            variables:
              comp_sensor: "{{ states.sensor.rolling_sprinkler.state | float(5.105) }}"
            mode: single
          - id: "1716578941208"
            alias: Water Garden Sprinkler
            description: Turn on the sprinkler for set time
            triggers:
              - trigger: sun
                event: sunrise
                offset: "-3600"
                id: Start watering 1 hour before sunrise
            conditions:
              - alias: Watering while raining is worthless
                condition: state

thusassistint · May 23, 2025, 9:49pm

I think this is possible with a statistics sensor like this:

sensor:
  - platform: statistics
    name: "Rain last five days"
    unique_id: uid_rain_last_five_days
    entity_id: sensor.rain_last_24h
    state_characteristic: sum_differences_nonnegative
    max_age:
      days: 5

This uses the “Rain last 24h” sensor from Buienradar, and sums all the values from the last five days.

thusassistint · May 24, 2025, 10:20am

Hmmm… I have to come back on this, because it isn’t functioning like I expected.
This statistics sensor works perfectly with my Netatmo rain sensor, but apparently the Buienradar 24h sensor behaves differently.
The Netatmo sensor counts the total precipitation for the current day, and this value is reset at 00:00 every day:

The statistics sensor handles that correctly, showing the total amount of precipitation for the last five days:

However, the Buienradar sensor gives the total amount of precipitation for each last 24 hours:

And the statistics sensor also counts the values when the amount goes down:

I did expect that only the values going up would be counted (nonnegative), but apparently it doesn’t work like that.

Perhaps it is possible to use the Buienradar sensor “Rain 1d” with a statistics sensor like this?
Anyhow, it of course is better to use real measured precipitation values, like with a Netatmo sensor, and not use predicted values like the Buienradar sensors.