明天可能要下雨用英语怎么说

"It's going to rain tomorrow"是表示明天可能要下雨的常用英文表达方式。

"It's going to" 是将来时的表达方式，"rain" 是下雨的意思。

例句：

"The forecast says it's going to rain tomorrow." (预报说明天可能要下雨。)
"I think it's going to rain tomorrow, so don't forget your umbrella." (我认为明天可能要下雨，所以不要忘记带伞。)
"It's going to rain tomorrow, I need to water my plants tonight." (明天可能要下雨，我今晚需要给我的植物浇水。)