noun, noun which may take the genitive case particle 'no'
Refers to the area outside a building, especially in contrast to being indoors. Slightly formal or written; in casual speech 外 (そと) is more common.
戸外で食事をするのは気持ちがいい。
Eating outdoors feels great.
戸外の気温は氷点下だった。
The outside temperature was below freezing.