下雨进行时英文怎么说

"It's raining" 是表示下雨进行时的常用英语表达方式。其来源可能源于英语中表示进行时的动词"to be" 与 "raining" 的结合。

例句：

It's raining heavily outside. (外面下着大雨)
I can't go for a walk, it's raining. (我不能出去散步，因为在下雨)
The forecast says it's going to rain all day. (天气预报说整天都会下雨)