Weather; the atmospheric conditions of a day (a somewhat more formal/written term than 天気).
天候不良のため、試合は翌日に延期された。
Due to bad weather, the match was postponed to the next day.
山の天候は急に変わることがあるので注意が必要だ。
Mountain weather can change suddenly, so caution is necessary.
天候を見て出発を決めましょう。
Let's decide departure based on the weather.