The astronomical beginning of spring is considered March 21, the day of the equinox. Naturalists, on the other hand, speak of March 19 as the beginning when the rooks arrive. The calendar spring includes three months, from March 1st to May 31st.
The spring season is found in temperate latitudes, while the tropical climate excludes its manifestations. This season is divided into three periods: early spring, middle and late.
There is still snow in early spring, and it lasts until the second half of April. The middle spring lasts until the bird cherry blossoms, that is, until the second half of May. Late spring ends in early June, a sign of which is the flowering of apple and lilac trees.
In March, the processes of awakening all living things are launched, the air gradually warms up. The air temperature is increasingly rising above zero, but the snow and ice are not yet melting. In the second half of March, the days are gradually lengthening and the nights are shortening.
The sun rises higher and higher above the horizon, and its rays are warming the earth more and more. In the second half, you can see the first cumulus clouds in the sky, they are formed due to the heating of the air. In the evening, the cumulus clouds disappear.
In early April, the snow is actively melting, turning into streams. From mid-April ice drift begins on rivers and lakes. Ice on the surface cracks under the influence of positive temperatures and breaks up into fragments.
Because of the melting ice, the rivers overflow their banks, floods begin.
In early May, it often gets colder, up to frost, which negatively affects the plants.
Trees begin to wake up in March, which is manifested in the process of sap flow. The roots actively absorb water from the thawing soil, and the reserves of nutrients are dissolved in it. This juice moves towards the kidneys.
After ten days, the buds swell, the wind-pollinated plants first bloom. These are alder and hazel. Of those pollinated by insects, the willow is the first to bloom.
In April, the trees are mostly bare, but the scales on the surface of the buds are already moving apart. The tips of the leaves are shown outward. Young leaves are usually covered with either a sticky substance or fluff.
Young leaves have a delicate color and high transparency. By the end of April, buds of birch and bird cherry blossom. In the first half of May - maple, yellow acacia, pear, apple.
Linden and oak buds bloom quite late.
In the second half of May, spring is rapidly gaining momentum, a number of plants begin to bloom at the same time. Bird cherry and black currant, strawberry and fruit trees, a large number of herbaceous plants bloom.
By the end of spring, the petals of the flowers of apple and lilacs crumble, the fruits of willow and aspen ripen. The next season begins - summer.