I want to ask the following question:
How does Google Weather get all data like temperature and wind etc. Of every city. Do they collect data from satellites?
On which Stack Exchange site would this question be on-topic?
I don't think that there is SE site for your question.
Web Applications could be the closest site, as the question could be about a Google (web search), but the scope of this site is about using a web application, not about the data sources per se.
As pointed out on a comment, also a similar question could be on topic on Android Enthusiasts as there are several Android apps that return weather results.
Maybe you could make a related question like where to check the data source of an specific query / result as Google could use several data sources as they love to "personalize" results, i.e. they could use different data sources for different cities due to any criteria that they want to use, like relevance, user rating, costs, A/B testing, etc.
Earth Science has a some way related questions:
Internet of Things also has a some way related question: