Number:Humidity and difference between absolute and relative humidity


I was wondering whether there was a reason why there is a Number:Temperature but no Number:Humidity. Is there a specific reason, or was it just not implemented yet? I could look into adding it, if that’s ok?
Also, I think semantically it might be important to differentiate between relative humidity (
%) and absolute humidity (water per volume). Would this be something that could be added?

Thanks for any help, greetings,

Because relative humidity is a percent which is handled by Dimensionless and absolute humidity is represented by a weight per volume which is also already handled by Density. There is no unit that is use to measure just humidity like °C, °F, and °K are used to only measure temperature.

It’s already there and I think it would be incorrect to invent a new proxy unit for humidity.

It’s already there. Relative humidity should use Dimensionless and absolutely humidity should use Density.

Perfect, thank you for the reply!

I’ve tried this, but now the measurement shows up as “52 one” (a literal “one” string). Did I do something wrong here?


Dimensionless is used for multiple types of measurements (see Units Of Measurement | openHAB) including percent, decibel, and parts per million. So you need to tell it which one you want to use here.

Add a State Description metadata to the Item and set the pattern to %.0f %% . The %% tells it you are after percent.

Thank you very much for the explanations, this solves my problems :wink: