With the Google Home app, you can change the weather unit to Fahrenheit or Celsius on Google Assistant-enabled devices linked to your Google Account.
- Make sure your mobile device or tablet is connected to the same Wi-Fi network or linked to the same account as your speaker or display.
- Open the Google Home app
.
- Tap your account.
Verify that the Google Account shown is the one linked to your speaker or display. If correct, tap Close
to return to the previous screen.
- To switch accounts, tap the triangle next to the Google Account, then tap another account or Add another account.
- Tap Settings
Google Assistant
.
- Tap Manage all Assistant settings.
- Scroll to the bottom of the page, and then tap Weather
.
- Choose your preferred weather unit.
.
Google Assistant 
.