outside a room or building; outdoors
Refers to the area outside a specific enclosed space, such as a room, building, or vehicle. Often contrasted with 室内 (inside).
The temperature outside the building is over 30 degrees.
In this room, you can clearly hear the noise from outside.
室外 means 'outside the room', contrasting directly with 室内 'inside the room'.
Compound of 室 (room) and 外 (outside).