Statistics Sensor Set to Sum Only Shows Average

Configuration
1

My statistics sensor which is set to srate_characteristix: sum results in an entity that shows the what looks to be the average precipitation

platform: statistics
  name: "Precipitation over last 12 hours"
  unique_id: rain_last_12_hours
  entity_id: sensor.home_precipitation
  state_characteristic: sum
  max_age:
    hours: 12
  sampling_size: 12

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I am tracking the following sensor:

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my Weather.com integration has a precipitation for the past 24hrs and 6 hrs which allowed me to confirm that the numbers my sensor is providing is incorrect.

What am I doing wrong?

Thank you in advance.

2

I think the issue is the sample size, 12 samples seems very low for 12 hour span. How often does the sensor update it’s value?

3

It looks like it changes as the value changes but I as I cannot identify a specific interval. But based on my need why does it matter? I think that I should only want 12 samples, one per hour and then add the total to get the amount of precipitation. I understand that it wouldn’t be extremely accurate but I just need a reasonable estimate.
Edit: I did find a sensor “Precipitation - Last hour” which I think will provide more accurate results but I am still concerned about the entity not displaying a total value

4

That would be fine if you know the source sensor produces only one value per hour. Samples are not evenly spread across the limit imposed by max_age. Only the most recent 12 values, within the time span of max_age, will be used.

5

That makes sense. I think that I was able to find a solution although I will only be able to tell after the next time I have precipitation. I made an input_number helper and, then via an automation, set it to the value of my sensor that provides the total precipitation in the last 24 hrs and then had it compare its value 12 hours later to the total precipitation in the last 24 hrs and output it to another helper. It isn’t very tidy but I think it will work