Colorful spring
During early spring, the axis of the Earth is increasing its tilt relative to the Sun, and the length of daylight rapidly increases for the relevant hemisphere. The hemisphere begins to warm significantly, causing new plant growth to "spring forth", giving the season its name.
Many flowering plants bloom at this time of year, in a long succession, sometimes beginning when snow is still on the ground and continuing into early summer. In normally snowless areas, "spring" may begin as early as February (Northern Hemisphere) or August (Southern Hemisphere), heralded by the blooming of deciduous magnolias, cherries, and quince.
Many temperate areas have a dry spring, and wet autumn (fall), which brings about flowering in this season, more consistent with the need for water, as well as warmth. Subarctic areas may not experience "spring" at all until May.
While spring is a result of the warmth caused by the changing orientation of the Earth's axis relative to the Sun, the weather in many parts of the world is affected by other, less predictable events.
In recent decades, season creep has been observed, which means that many phenological signs of spring are occurring earlier in many regions by around two days per decade.
"When daisies pied and violets blue
And lady-smocks all silver-white
And cuckoo-buds of yellow hue
Do paint the meadows with delight,
The cuckoo then, on every tree,
Mocks married men; for thus sings he,
Cuckoo;
Cuckoo, cuckoo: Oh word of fear,
Unpleasing to a married ear!"
"When shepherds pipe on oaten straws,
And merry larks are plowmen’s clocks,
When turtles tread, and rooks, and daws,
And maidens bleach their summer smocks,
The cuckoo then, on every tree,
Mocks married men; for thus sings he,
Cuckoo;
Cuckoo, cuckoo: Oh word of fear,
Unpleasing to a married ear!"
Song: Spring
By William Shakespeare