Humidity is very hard to get straight answer. It´s one of the hardest issues to get by, when dealing with an AI like voice recognize cause, in this case, Google is simply too stupid…
You´ll have to ask Google exactly the correct phrase (and very specific) each time…
Examples: (Direct translated from danish into english, cause I use danish):
“Hey Google, what is the humidity in (room)”.
This will respond in either, “sorry I cant…”. Because you´re asking the wrong question.
Or it it will grap a humidity value from the internet "The humidity in blablab country/town/whatever is… ", because it thinks you´re asking about the humidity in that place.
Then I have even tried the most correct question to ask,
“Hey Google, what is the relative humidity in (room)”. This will fail just like the above.
But if I use,
"Hey Google, what is the air-humidity in ". (notice the “air” infront of humidity)
It works, and it always respond with,
“The thermostat in (room) shows humidity is…(value)”.
Having a Google Nest/Home hub, it´s easy to visually see, whats going on, and when things are going wrong, cause it will show the exact text it receives (or it assume). I use it alot (several times a day).
You can do the same from a phone by using the Google Assistant app. It will show the same.
Small side note:
Sometimes google will respond with,
“Right now the thermostat in (room) shows humidity is (value).”
I havnt quite figured why there seem to be a difference in a correct answer. I think its because Google is trying to act more “human” by giving different ways of the correct answering.
I have 12 thermostats. 10 are exactly the same, and is setup the exact same way. 2 thermostats have humidity sensors, and is setup exactly the same as well. Even though, Google will respond different if I ask for temperature in my livingroom or in my kitchen… Its very strange…
But thats just a side note.