There's an old sailors' poem: "red skies at night, sailors delight; red skies in morning, sailors take warning.” Is this a saying we should trust and follow? Let's look into it! First, we need to understand why we see colors in the sky. The colors we see are due to the rays of sunlight being split into colors of the spectrum as they pass through the atmosphere and ricochet off the water vapor and particles in the atmosphere. The amounts of water vapor and dust particles in the atmosphere are good indicators of weather conditions. They also determine which colors we will see in the sky. Why is red the color used to measure this? Because it is the longest wavelength. So, the shorter wavelengths get scattered by the high concentration of particles, but red makes it through. So, red indicates high levels of particles in the atmosphere. When the sunset is beautifully red, sun is shining on dust particles are are being pushed by high pressure systems known to bring warm dry air. This basically can indicate stable air, and good weather on the way. When the sunrise is a deep red, though, a low-pressure system might be pushing moisture toward you, indicating rain could be on the way. But, there are a lot of EXCEPTIONS, and this is really only a perfect predictor in ideal situations: - Works best at middle latitudes, because of westerly winds being the predominant winds - Storms don't always more in the same direction - Incoming/outcoming pressure systems might both have clouds that confuse you. - Sometimes, sunsets and sunrises are red for other reasons. Even though these techniques are not always accurate but something to pay attention to. With this knowledge, as well as knowledge of other ways to ID weather changes, you'll be able to make the right call about upcoming weather changes!