Questions & Answers about Каково на улице?
Here каково means something like what is it like or how is it. So Каково на улице? is asking about the general conditions outside.
This is an impersonal way of speaking. English usually needs a subject like it, but Russian often does not. So the idea is basically What’s it like outside?
Каково is a more specific, somewhat more literary or formal way to ask what is it like?
Compare:
- Как на улице? = How is it outside? / What’s it like outside?
- more conversational
- Каково на улице? = What is it like outside?
- a bit more formal, reflective, or bookish
So both are understandable, but каково has a slightly different tone.