I don't work with Google Home and use Netatmo via the app.

The question is a bit older, but I came across it here while looking for a solution. Netatmo currently has a clear answer to this problem. Unlike other Netatmo products, the weather station is not currently supported by Google Assistant:
https://helpcenter.netatmo.com/de...

I have been trying to connect the Netatmo station for over two years now. Unfortunately, it still doesn't work. Although the support page of the weather station says how it should be done and what commands there are.
What else I have now found out:
Apparently the problem here is not with Netatmo, but with Google. So you can connect Netatmo products, but not temperature sensors. The Netatmo thermostats, on the other hand, should work perfectly.
Google is therefore blocking temperature queries. Whatever the reason.

I can now connect Netatmo weather station with Google Home. I received a notification on my mobile phone on Sunday. This is probably possible due to an update of the weather station.

The temperatures are now displayed in Google Home.

I have also not managed to operate it with Google Home or Assistant, the ifft does not help here either

I only use Netatmo for occasional polling and the log in via the app or website is sufficient.