I find a issue as in silverblue weather app usually installed from fedoraproject repo as flatpak. But for every city’s i have tried it always set to °F for temp output for both C or F it always shows F in notification Area.
Gnome weather issues isetting it to °C it still shows °F in notification area
On a Fedora Workstation, you can set the temperature unit as follows:
gsettings set org.gnome.GWeather4 temperature-unit "centigrade"
Check if this works for you.
i just remove that and overlay with gnome-weather.rpm and set that as C and now it just changes from F to C without a issue.
i have tested on my both systems running silverblue so i find it is a bug so can you try on your system if installing it as flatpak creates this issue that changing to C does not change notification area weather. if that is the case here i will file a bug.