Nature and all living beings have always followed the rhythm of the sun and the seasons. In summer we look forward to long, warm evenings and in winter we enjoy cozy hours at home while it's cold and dark outside. At the North and South Poles there are even times during the year when the sun no longer sets or rises at all – also known as the phenomenon of polar days and polar nights. The reason for these differences lies in the rotations of the earth around itself and around the sun and the inclination of its earth's axis to the sun.
The earth's axis
Our earth moves like a spinning top through our universe. It rotates around its own axis once a day. This axis can be compared to a straight line connecting the South Pole, the North Pole and the center of the earth. Whenever our place of residence faces the sun, we feel the light of the sun and it is day. As soon as it continues to turn and we are now back on the side facing away from the sun, it will be night again. This rotation takes about 24 hours and is therefore the basis for our day length.
The tilt of the earth's axis
At the same time as it rotates around its own axis, the sun rotates around our sun within a year, also called a solar year. If you think of the area inside the Earth's orbit as a flat disc, this results in what is known as the ecliptic plane. The seasons and the different lengths of our days in winter and summer depend decisively on the inclination of the earth's axis to the ecliptic plane. The Earth's axis is not at right angles to this plane, but is currently tilted at about 23.4 degrees in comparison. Due to this tilt, either the northern or the southern hemisphere of the earth is always inclined further towards the sun and a larger area is illuminated – seasons are created. The more perpendicular the sun's rays hit the earth, the warmer it gets and the longer the days become. Conversely, the sun's rays hit the surface of the earth more and more obliquely with increasing distance, on the hemisphere that is inclined towards the sun. That means the days are getting shorter and it's getting colder.
The closer you get to the equator, the smaller the differences in day length and the seasons slowly disappear. At the equator itself, the differences are almost completely blurred. The days and nights are almost the same length, namely 12 hours, and the climate changes only minimally over the course of the year. The sun's rays hit the earth's surface here all year round at an almost vertical angle, which means that it is hot all year round and the climate is tropical.
Days at the North and South Poles
In the polar regions, the exact opposite effect occurs and you can experience the phenomenon of polar night and polar day. Around the winter solstice on December 21st or 22nd, the sun does not fully rise above the horizon between the arctic circles and the poles for at least one day. At the pole itself, this phenomenon can last for several weeks or even months. The polar day is the opposite of the polar night – here the sun does not set for at least one more day in the period around the midsolstice on June 21st or 22nd. This means that the midnight sun no longer sinks below the horizon and apart from a small midnight twilight it is light the whole day.
Winter and midsolstice
Even in the temperate latitudes Winter and midsolstice are the longest and shortest days of the year, respectively. The winter solstice in particular is eagerly awaited by many people. From this day on, the days are getting longer again, the northern hemisphere is slowly tilting towards the sun again and it is getting warmer.
Through the With the rotation of the sun and its oblique axis, we experience an impressive change in the length of day and night and the seasons emerge. This phenomenon affects the rhythm of life of all living beings and all of nature and shows once again how extraordinary and impressive our planet is.
Conclusion: When does the sun rise in summer & in winter?
In January, in the middle of winter, the sun rises at around 9 a.m. In summer, on the other hand, the sun rises at around 5-6 a.m.