When we see scenes like in these pictures, where we see parts of the land exposed to sunlight and the other side there is covered by clouds, what term might we use for that condition?
In general, it is a mix of sun and clouds. Some say that. Or it is also called partly cloudy or partly sunny. But if we want to mention the conditions of the sky more scientifically, we can refer to the official terms that have been given about the average amount of sky cover (check here), and what is termed a fair sky, according to this reference, is less than 40% cloud cover, no precipitation and no extreme weather. Or as another source says:
"Technically, it means that less than three oktas are covered with opaque clouds, and that there’s no precipitation, no extreme conditions of visibility, wind or temperature, and generally pleasant weather."