The sun appears to set at right angles to the horizon. Closer to the poles, the sun takes a more leisurely angle through the sky.
It rises near the east, does not go straight up, does not get as high as the zenith at midday and sets near the west. You can see clearly that it takes a lot less time to get dark at the equator than it does even in Key West.
As we move northwards, away from the equator, that time gets longer still. At the equator, in Quito, nautical twilight starts only 20 minutes after sunset, compared with 23 minutes in Key West, 26 minutes in Kansas City, and 44 minutes in Anchorage. In Quito, it only takes just over an hour 68 minutes to get dark after sunset at the spring equinox. Move north from there and it takes 76 minutes in Key West, 90 minutes in Kansas City and almost 2 and a half hours up in Anchorage.
Whatever your location, though, it takes slightly longer to get dark the closer to summer we are. The difference is small, being only a few minutes for mainland USA. Take Alaska, for example. Closer to the poles, the Sun takes a more gentle angle through the sky; therefore, it takes more time to get dark. Apart from the proximity to the equator, another factor to consider is the altitude. Later, sunsets can be observed in high mountains as the horizon is lower.
An interesting phenomenon was also noticed in the mountain area: double sunset. The Sun vanishes after a part of the mountain only to reappear on another part before setting ultimately. The same happens in the cities with really tall buildings. However, the phenomenon lasts only 3 minutes. During the year, the Earth changes its position around the Sun, which affects the lengths of the night time.
However, for most of the areas, the difference is not significant just a couple of minutes , but it gets more enjoyable while you go up North.
In some cases Alaska , during the summer months, there is no night at all. The phenomenon is known as Midnight Sun, and it is quite essential for the locals and not only. However, during the winter months, the folks living at the poles experience the Polar Night when the night lasts more than 24 hours. However, it is not entirely dark everywhere in the polar circle but only in regions within 5. The rest of the places just have more twilight than equatorial regions.
Two times a year, the daytime equals the night. These events are known as Equinoxes , and they happen when the center of the Sun is right above the equator.
The Solstices mark either the longest day of the year in June or the shortest in December. But things tend to get complicated really quickly, so take your time trying to wrap your head around it. The December solstice is the time when the Sun reaches the most southerly point in the sky. This results in the longest day of the year in the southern hemisphere. This makes the December solstice the Summer solstice in the south. For the northern hemisphere , the June solstice is the summer solstice , so the longest day is in June.
One would easily think that the summer solstice should have the earliest sunrise and the latest sunset — it makes sense because that would allow for the longest day easily. But this is not the case in most places. That is, just like the previous example, very logical, but the truth is different.
When the North hemisphere is experiencing summer, that is because the North is tilted towards the Sun and receives more sunlight than during winter. The opposite is true for the South hemisphere. Altitude obviously makes a difference in Sunset time. This is a rare phenomenon in areas which have tall mountains nearby. The Sun sets behind a part of the mountain but re-appears behind a different part of the mountain before setting again.
But in modern times, a different type of double sunset is also possible. The building Burj Khalifa is so tall that you can watch a sunset twice during the same day.
If you watch a sunset at the ground, then take the elevator, you will be able to experience a second sunset. The difference is most often around 3 minutes. Here we will have a table with sunset and twilight times across a few major cities in the world. You will see that during the same day, the sunset time will be drastically different because of the different conditions described before.
We will provide a table for July and one for January so that you can see how big the differences can actually be during summer and winter. Keep in mind that places in the South hemisphere have the seasons inverted when compared to the northernern hemisphere. For clarity and precisions, we will use the 24h system also called military time. As you can see, there are quite a few peculiarities going on throughout the world.
During summer, it can happen that a place does not experience a real night at all. That, of course, does not mean that the outside is bright. The astronomical twilight is, by most standards, complete darkness — it is only in an astronomical sense that it is not totally dark, meaning that some very faint objects are difficult to detect with telescopes.
You can also notice that there are quite big differences in the dawn and dusk times in different seasons. During winter you will have more time to explore the darker phases, making it slightly better for astronomy as long as it is not too cold to operate equipment, while summers are somewhat better suited for cameras and photography.
But, of course, each season allows you to take different pictures and explore different objects. And you should not forget the crossover hobbies like terrestrial telescope exploration and astrophotography. A fun fact — there are no seasons around the equator because the alignment towards Sun stays constant throughout the year! To summarize: the exact time of sunset and sunrise are very difficult to calculate without a lot of experience, even when talking about a single city.
There are many factors that will impact your hobby. What we recommend is using a website to calculate the exact times. By finding the correct times of different types of twilight, you will be able to plan accordingly and use your time more efficiently to get the best shots possible or to find the best time to locate certain objects. Depending on your sleep and work schedule, this might be a very important part of your hobby.
Here is a website we have used to find our data on the different twilight times. It will provide you with a visual representation, the exact duration of different types of twilight, as well as with the duration of day and night. It probably goes without saying that sunset is the time at the end of the day that the Sun disappears on the edge of the world. No matter where in the world you find yourself, the Sun will always set in the western sky.
After the sun completely sets, evening transitions into a period of twilight until complete darkness sets in. During this time, the Earth goes through a gradual period transitioning from light to dark. This stretch of time is known as twilight. To put those degrees into perspective, hold the three middle fingers of one hand out in front of you as far as you can.
The distance between those three fingers is around five degrees. Although the Sun is no longer present, its presence remains. The sky may have turned a myriad of colors, but it is far from dark.
Only the very brightest objects, such as the Moon, Venus, Jupiter, and Sirius, may become visible. Individuals experiencing civil twilight see light start to fade but are still able to go about business without the need for artificial light.
The term nautical twilight dates back to an era where sailors could use the stars during this time for navigation. Most stars are visible with the naked eye, the horizon is still visible, and there is still some natural light to be able to function. Almost all the sunlight has faded away as the evening enters astronomical twilight.
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