About the only thing about the weather I can tell from my window is whether it is currently raining or not.

The temperature inside is not at all indicative of the temperature outside, the sun being out doesn't mean it is warm, and I don't really have any useful indicators of wind, unless the windows are rattling, but that doesn't let me know if there's a stiff breeze.

I could walk over and open up my balcony door and experience it all personally, but checking my phone or watch is faster and more accurate, and also gives me the forecast at the same time.