Save for a rainy day

　　未雨绸缪

　　例句：We save money for a rainy day.

　　It never rains but it pours

　　不雨则以，一雨惊人

　　例句：I just got sacked and my wife left me！So it never rains but it pours！

　　right as rain

　　身体健康，一切正常

　　例句：I was sick，but now I feel as right as rain.

　　和云有关：

　　on cloud nine

　　飘飘然如上九重天

　　例句：She passed the auditon and now she is on cloud nine.

　　head in the cloud

　　不切实际，好高骛远

　　例句：You can't always have your head in the cloud，you need to be down-to-earth.

　　和彩虹有关：

　　chase rainbows

　　做白日梦

　　例句：Chsing rainbows won't get you anywhere.

　　和风有关：

　　sail close to the wind

　　冒险

　　例句：If you believe what he said， you are sailing close to the wind.

　　know which way the wind blows

　　了解情况

　　例句：He never tells his thoughts until he knows which way the wind blows.

　　和雪有关：

　　be snowed down

　　工作太多做不过来

　　例句：I've been snowed down by my work！

　　white as snow

　　纯洁无辜

　　例句：The accused didn't comitt the murder，he is as white as snow.

　　和天气有关：

　　fair-weather friend

　　泛泛之交

　　例句：A true friend is the one who shows up when you are in trouble, a fair-weather friend is the one who shows up when you are in happiness.