Some of the text on some of the widgets are not translatable.
Below is a list of the places I found where this occurs:
Weather widget with the time/date/location, abbreviated dates and "data from" text (highlighted in red below)
On the location picker on the weather widget
For the example search in the calculator widget:
The date on the clock widget:
Languages and "Search language..." in the translation widget:
All text displayed by widgets should be translatable