You will need to configure a page to include the Temperature Data Cell. A preconfigured page can be found on the Elevation page which displays altitude, grade, ambient temperature & total climb.
On the Wahoo App:
1. In "Settings", select the workout profile you wish to edit (e.g. Biking) to open the preference screen.
2. On the workout preference screen scroll to the bottom and select "Workout Pages".
3. Select the "+" icon on the centre right side of the screen and choose the "Elevation" page to enable it.
4. If you wish to then remove this page, select the page you wish to delete and swipe up from the bottom of the screen and select "Delete Page".