Q: Is the saying “red sky at night, sailorâ€™s delight, red sky at morning, sailor take warningâ€ really accurate?
A: Generally, the answer is yes, says Brent McRoberts of Texas A&M University. The saying has been around for thousands of years and is even mentioned in the Bible in the book of Matthew: “When in evening, ye say, it will be fair weather, for the sky is red; and in the morning, it will be foul weather today, for the sky is red and lowering.â€ The saying, McRoberts notes, “may be the most famous of all weather lore. It goes back to the observations made by sailors who had a clear 360-degree view of the horizon from the shipâ€™s masts. In the northern hemisphere, most weather patterns move from the west to the east, so if a sailor could see a red sunset to the west, it meant that skies were clear in that direction and that tomorrow would likely be a nice day with few clouds.â€
Q: What is the science behind the saying?
A: When the sky is red at night or sunset, it is caused by the sun striking particles in the atmosphere. “But if a sunrise has a reddish tint or looks rosy colored, and you can see clouds over the horizon, it might mean the nice weather has passed and a storm system is headed your way,â€ McRoberts adds. “It means an area of low pressure could be moving in, and low pressure almost always means clouds and often rain or thunderstorms.â€