早霞不出门；晚霞行千里。Zǎo xiá bù chū mén; wǎn xiá xíng qián lǐ.
Literally means "if you see rosy clouds in the morning, you’d better not go out, as surely it will be raining soon; if you see a sunset glow you can go traveling the following day."
English equivalent: “Evening red, morning grey sends the traveller on his way; evening grey morning red, bring the rain upon his head.”
Example sentence: 昨天的晚霞非常漂亮，今天一定会是晴天。因为人们说：早霞不出门;晚霞行千里！
Zuótiān de wǎn xiá fēicháng piàoliang, jīntián yídìng huì shì qíngtiān yīnwèi rénmen shuō: zǎo xiá bù chū mén; wǎn xiá xíng qián lǐ!
“There was a very beautiful sunset yesterday, today surely will be a sunny day. As people say: "Evening red, morning grey, send the traveller on his way; evening grey morning red, bring the rain upon his head.”