it will rain和it's going to rain的區別

有區別,It's going to rain.表示“（有某種跡象）要下雨了.”； 而 It will rain.則不能表示有某種跡象,壹般用於表示“（收音機或電視天氣預報）將要下雨.”

如：Look at the black clouds.It's going to rain.

The radio says it will rain tomorrow.