天有不测风云， 人有旦夕祸福

天有不测风云， 人有旦夕祸福 [tiān yǒu bú cè fēng yún rén yǒu dàn xī huò fú]

1. ■ In nature there are unexpected storms and in life unpredictable vicissitudes.; Human fortunes are unpredictable as the weather.; Unforeseen, into storm can nature burst; Overnight, a man may have his fortune reversed.; Storms gather without warning in nature, and bad luck befalls men overnight.; Sudden storms spring up in nature and men's fortunes may change overnight.; The unexpected always happens.