It's raining cats and dogs.

下大雨了。

When it's raining cats and dogs.

当下猫和狗的时候！

It's raining cats and dogs outsides.

外面下着倾盆大雨。

The hiking is cancelled since it's raining cats and dogs.

徒步旅行被取消了，因为下着倾盆大雨。

Thee hiking is cancelled since it's raining cats and dogs.

徒步旅行被取消了，因为下着倾盆大雨。 。