❌ It will be rain tomorrow.
It’s going to rain tomorrow.
It's going to be rainy tomorrow.
It will rain tomorrow.
We'll have rain tomorrow.
雨が/は
▸ 今ひどく雨が降っています
It's raining hard [drizzling] now.
▸ しとしと雨が降っています
It's raining hard [drizzling] now.
▸ あすは雨が降るだろう
It will rain tomorrow.
We will have rain tomorrow.
(話し手のいる場所について述べるときは It より We を主語にする方が多い)
▸ 雨が降り出した
It started to rain.
The rain began [started] to fall.
▸ 雨が降りやんだ
The rain has stopped.
▸ 雨はやみそうになかった
The rain showed no sign of letting up.
▸ 今年はあまり雨が降らなかった
We haven't had much rainfall this year.
▸ 今朝から雨が降ったりやんだりしている
It has been raining on and off since this morning.
The rain has been coming and going since this morning.
▸ 雨がだんだん強くなってきた
It's raining harder.
The rain is getting heavier.
▸ 家を出た時は雨がひどく降っていたが, 今は小降りになった
It was raining hard when I left home, but now it has let up.
▸ 曇り時々雨 (天気予報で)
Cloudy with occasional showers.