Refers to the sky above a particular location or at high altitude, often used in weather, aviation, and observational contexts.
The airplane is flying above the clouds.
上空の気温は氷点下だ。
The temperature in the upper air is below freezing.
The airplane was flying over the skies above Tokyo.
Thick clouds are spreading across the sky above.
The typhoon passed over the skies above Kyushu.
This plane flies at an altitude of 10,000 meters.