Rainy weather; conditions when it is raining (somewhat formal term).
雨天のため、試合は翌日に順延された。
Due to rainy weather, the match was postponed until the following day.
雨天の場合は屋内で行います。
In the case of rainy weather, it will be held indoors.
雨天でも作業が必要な現場は大変だ。
Sites that require work even in rainy weather are difficult to manage.