Winter is ending, spring is coming: what is the difference between the calendar and meteorological beginning of spring? All information about the season.
The most important things at a glance
Butterflies in the stomach and on the flowers, sun on the skin and in the heart: When the migratory birds return and spring finally comes back to the calendar, not only plants bloom. We too feel the new season. But does spring begin on March 1st? The answer is yes.
When is the beginning of spring?
There are three different dates:
- Calendar beginning of spring: This day is also called the astronomical beginning of spring or the equinox. On this date, day and night are exactly the same length. Because the inclination of the earth’s axis to the sun changes over the course of the year, the seasons arise. Spring in the northern hemisphere begins when the sun is exactly at its zenith over the equator and “moves” north. This year, that is March 20, 2022 at 4:32 p.m.
- Meteorological beginning of spring: Weather scientists prefer to calculate their climate data in whole months. For them, spring therefore begins on March 1st and ends on May 31st.
- phenological spring: The beginning of spring can also be read in the home garden – depending on which plant is blooming at the moment. Phenology – Greek for “doctrine of phenomena” – derives the individual spring phases from this. When hazel bushes and snowdrops are in bloom, for example, the so-called early spring has arrived.
In the Middle Ages in particular, people tended to follow the phenological spring and introduced farming rules that are still partially valid today.
Why are our hormones going haywire?
Just like plants, people turn towards the sun as soon as the first rays break through the clouds. So it’s no wonder people flock to parks and cafes as the sun comes out after winter and day length increases.
In spring, the sun is higher in the sky again, which means that more sunrays reach and penetrate the skin. Once the UV-B radiation has reached the thin epidermis, the body begins to produce a substance that has long been underestimated: vitamin D.
Is vitamin D important?
Vitamin D is actually not a real vitamin, but an essential hormone. We cannot take in enough with food, so we have to go outside regularly. From studies with submarine drivers who do not see the sun in their tin tube for weeks, we know that we can store vitamin D. But the supply will probably only last for a few months. At the latest after the dark winter, many Germans have a shortage – and long for the sun.
The scientific name of the hormone reveals just how valuable vitamin D is: calciferol. The hormone helps to transport lime (calcium) to where it is needed – in the bones and muscles. So in spring our muscle strength increases, the bones become denser and therefore more stable. A day outdoors makes up for eight days without sunlight.
Why are we so tired in spring?
The sun’s rays not only have an effect on the light, but also on the heat. Some researchers explain the springtime fatigue that affects so many. So you have to imagine the first days of spring as a very mild permanent sauna: the heat dilates the veins, blood pressure drops, we feel tired and listless at first. Once the organism has adapted, spring fatigue is over.
Are spring fever an old wives’ tale?
The mystery of spring fever remains. Why is it that this event makes us feel fresher, happier and perhaps more attractive? We not only benefit from the sun’s rays on our skin. Much more light also falls on the retina in the eye than in winter; even the sunniest winter day only gets as bright as a dull summer day. The spring light now inhibits the production of melatonin in the brain via receptors in the retina. Especially in winter, this “sleep hormone” made us tired and listless.
The less melatonin is formed, the better serotonin can work. Serotonin is considered the “happiness hormone” and depressives suffer from a lack of it. The more light, the more serotonin. So spring is a kind of free light therapy.
Is spring bad for us?
However, spring does have one downer: UV-B radiation, which is so important, is only available together with UV-A radiation – and that causes the skin to age. So we’re getting wrinkled, but we’re stronger, happier, and healthier. Or, loosely based on Hesse: Every blossoming is inherently withering.
Does spring begin when the thermometer hits 15 degrees?
No, temperature alone is not a clear indicator of spring. 15 degrees can feel quite warm after a long winter. Nevertheless, “there is no definition of a spring day that is linked to the temperature,” explains Andreas Friedrich from the German Weather Service (DWD). One reason: In March, even lower temperatures with lots of sun can appear spring-like.
In other areas of meteorology, there are definitely fixed values: summer days begin at 25 degrees in the shade, on tropical nights the thermometer does not slip below 20 degrees at night. On frosty days it is at least once colder than zero degrees. And on ice days, the temperature stays permanently below zero degrees Celsius.
