You will be given a definition of a task first, then some input of the task.
You are given a passage. You need to construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) its answer is the whole paragraph. Avoid creating questions that can be answered correctly without actually understanding the paragraph.

Well to be more precise:

The mass of rain within a cloud directly affects how much light actually passes through, as the rain mass is somewhat of a solid entity, the light finds it hard to actually pass through.

Snow clouds, and banks, ect are of equal mass, but not density. Snow is inherently lighter than that of rain, which makes the light pass through them more efficiently.

Also, you have to understand that the cloud is still producing rain, however within the colder altitudes above the surface the rain is eventually forzen into snow/ice. Because of this, the cloud releases light at a much faster rate than a true rain cloud would, allowing the light to reflect off the falling ice/snow.
Output:
Why is it dark when it rains but not when it snows during the day?