Question about weather reporting (WoW classic WotLK)

[glitterguts]

Hi all, I want to make an addon that reports which zones are raining and on what layer. It's the only addon I want to make, so I have some questions I need answers to before I even begin learning how to make addons:
1. Is this data possible to access?
2. Would it only be able to pull weather data for the continent I am presently on?
3. Would layer reporting require other people have the same addon?

Thank you!