For those willing to wake up at an ungodly hour to battle puffy eyes and tangled hair to watch sunrise, the rewards can be stunning. Especially for photographers.

A good tip for sunsets is to avoid those on humid days, as humidity dulls the beauty of a colorful sky.

Daylight

When determining the timing of sunrise or sunset, it’s important to consider daylight. The amount of sunlight available at a given time influences the colors of the sky, as well as how vibrant or muted the scene is as the lighting will enhance the sparkle and beauty. If you’re only shooting a sunset or sunrise, the lack of sunlight won’t be as much of a concern, but if your goal is to capture an image of another subject with a gorgeous sky in the background, then it will matter a great deal.

The length of daylight varies throughout the year, due to the Earth’s rotation on its axis and orbit around the sun. The variation is smaller at the equator, where the length of the day remains nearly constant. However, at higher latitudes, the length of the Sun’s track across the horizon varies considerably more than it does at lower latitudes, which affects both sunset and sunrise times. This is called the geometric effect, and it is the main reason that at high latitudes, the dates of earliest sunset and latest sunrise shift by approximately an hour over the course of one year.

Cloud cover is also a major factor in determining whether or not you’ll be able to witness a spectacular sunrise or sunset. A lack of clouds can muted the beautiful reds and oranges of a sunset, while too many clouds can block the Sun’s rays from reaching the ground. The best locations for beautiful sunrises and sunsets are generally coastal or mountainous, as the horizon is more easily visible from these positions.

A recent study of Instagram photos used a combination of natural language processing and topic modeling to analyze human global reactions to sunrises and sunsets. The authors analyzed two datasets of geo-referenced Instagram posts to determine what aspects of sunset and sunrise are most highly valued by users, and where these preferences are most prevalent. They identified several patterns that indicate how users perceive and value sunrises and sunsets, including the perception that they bring tranquility, a sense of peace and a feeling of renewal. The researchers also found that users are especially attracted to sunrise and sunset photos with a wide expanse of color.

Cloud Cover

One of the most important factors in a beautiful sunrise or sunset is the clouds. The type of clouds, their height and the percentage of sky they cover are all crucial in creating a brilliant sunrise or sunset. If there aren’t enough clouds, or if they are the wrong type, it can ruin an otherwise spectacular scene.

The way that clouds affect a sunset is by scattering light. This means that some wavelengths of light are filtered out, while others are allowed to pass through. Red wavelengths are more likely to be scattered than blue or green, which is why sunsets are often more red than other colors. Ideally, you want to have a clear atmosphere where all wavelengths of light can pass through, but the type of cloud is also important.

Low clouds, for example, can cause a dull sunset because they block the sun from the horizon. However, mid-level clouds and high clouds can still create a gorgeous sunset because they reflect the sunlight over a larger area.

Another important factor when predicting the quality of a sunrise or sunset is moisture. Humid air is bad because it makes it difficult for light waves to scatter. This can make it hard to get that vivid color we are all so familiar with. A light rain is good, however, because it cleans the atmosphere and allows for more scattering of light.

A great activity to do at home with students is to observe how much of the sky is covered by clouds. This is easily done by having the students stand back to back and each stretch out their arms until they touch those of the student in front of them. The students should then observe how much of the sky is covered by these clouds and write it down. They can use this information to calculate the percentage of sky that is covered by clouds, which can be compared to data from satellite observations. Using this method can help students learn about how to determine celestial events and how to predict the weather.

Time of Day

As the sun moves across the sky, its apparent track is shifted from east to west by the varying amount of refraction of light in the atmosphere at different times of day. This effect is known as the geometric effect, and it can add up to a few seconds of difference in sunrise or sunset timing depending on where you are located. The change is most dramatic near the poles, where it can be several minutes.

There’s also the clock effect, which is the variation in the time it takes the sun to rise or set at any particular latitude. This is caused by the fact that the Earth rotates at an angular rate of 15° per day, which causes the time it takes for the sun to reach its highest point or sink to its lowest on any given day to vary. The result is that on October 15, for example, the sun rises one minute earlier than it did on October 14, while it sets at a minute later.

The time it takes for the sun to dip below the horizon is also influenced by the distance from the equator and its path through the atmosphere. For example, a sunset will last longer when New York City is closer to the equator than it will at the north pole because the sunlight is more oblique at the latter location.

Aside from these effects, sunset or sunrise times are largely determined by the fact that the sun has to be in position at the exact moment when the twilight period begins or ends, and this isn’t as easy as it sounds because of the way the Earth’s atmosphere bends light. The only really accurate way to determine the exact moment of sunrise or sunset is by using a device with a built-in horizon scanner, but even this has limitations because it requires an unobstructed view of the horizon and can’t measure the variations in refraction caused by clouds.

In addition to this, a good sunset or sunrise is also dependent on the weather conditions. High humidity and cloud cover can mute the brilliant colors of the sun, while low clouds can block its appearance altogether. A clear sky is required for a stunning sunset or sunrise, so it’s important to check the local weather forecast in advance and prepare accordingly.

Location

The time of day that a sunrise or sunset occurs is largely determined by the location where the event happens. This is because the Earth rotates, causing different parts of the planet to be exposed to sunlight at different times. The tilt of the Earth’s axis and its position in orbit around the Sun also influence when these events occur.

In addition, altitude plays a role in how early or late the Sun rises or sets. For example, a mountaintop will see the sun rise and set at an earlier or later time than a flat coastal area because the Sun has to travel farther up or down to reach it.

Because of this, it’s possible to see very different sunrise and sunset photos depending on the exact location where they were taken. The photo above, for instance, was taken at the Grand Canyon, which is at a much higher altitude than New York City, where this photograph was taken. This difference in timing can affect the quality of the photos, especially if there is heavy cloud cover at the time of the sunrise or sunset.

Another factor that influences the timing of a sunrise or sunset is the country’s latitude. The closer to the equator, the more evenly the Sun’s daily track above the horizon is spread out throughout the year. At the same time, the Sun’s track above the horizon is more oblique in the northern hemisphere than it is in the southern hemisphere.

This means that the times of a sunset in the northern hemisphere are different than they are in the southern hemisphere, which can cause confusion for people who travel between regions. This is why many people who are not familiar with the astronomical patterns of the Sun will use a calendar to determine when to travel to certain destinations for the best chance of seeing a beautiful sunrise or sunset. For example, the 2024 Farmers’ Almanac has a sunrise and sunset calculator that can be adjusted for various locations. The tool uses the cosine similarity metric to identify areas where sunrise and sunset reactions form similar spatial patterns.