Here's an old country saying for judging the likely weather to come, that's actually a mnemonic rhyme:
A red sky at night, shepherd's delight,
At sundown, an evening sky appears red in the west when thin high clouds are present to reflect the dying light. Such high clouds usually indicate a warm and dry night without rain the next day. However a reddish tinge in the sky towards sunrise usually indicates the opposite, due to lower clouds of a different nature. At sunrise the early presence of such clouds combined with an obvious rising temperature usually brings rain before too long!
According to Brewster's Dictionary the Italians also have a saying that is somewhat similar:
Serra rosso et negro mattino
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