ADJ-GRADED (时期、季节等)多雨的 During a rainy day, season, or period it rains a lot.
They walked along the promenade on a rainy night... 他们在一个雨夜沿着海滨道散步。
The rainy season in the Andes normally starts in December. 安第斯山区的雨季通常在12月份来临。
PHRASE 以备不时之需;未雨绸缪 If you say that you are saving something, especially money, for a rainy day, you mean that you are saving it until a time in the future when you might need it.
I'll put the rest in the bank for a rainy day. 我要把余款存入银行以备不时之需。