Why is it red sky at night shepherds delight?
Here’s a really simple explanation, to reinforce what some here (who have given correct answer) were trying to say: To have a red sky at sunset, there must be breaks in the clouds on the western horizon (the sun sets in the west), which allows the sun to reflect off the bottom of the lingering clouds. If there are breaks in the clouds to the west, that typically means that clearer skies are moving in (since weather typically moves from W to E). It’s that simple, and it’s not always correct.