I think I understand what's happening here. If I click the temperaure on launcher, it opens the Google Search app querying for "weather" - here it is in celsius.
Temperature units preference is saved in Google Search app. Pixel launcher, even though it shows the news cards from Search app, cannot show temperature in the units of my choice unless I give it the "Web and App activity" permission. Just Google things.
Temperature units preference is saved in Google Search app. Pixel launcher, even though it shows the news cards from Search app, cannot show temperature in the units of my choice unless I give it the "Web and App activity" permission. Just Google things.