It's raining outside.
Meaning: This means water droplets are falling from the sky beyond the walls of a building.
Choice of Words: It refers to the weather, raining means precipitation in the form of water droplets, and outside indicates a location beyond the walls of a building. When you put them together, "It's raining outside" describes the weather condition where precipitation in the form of water droplets is occurring beyond the walls of a building.
Alternative Expressions
Related Expressions