Seasons

A season is a division of the year, marked by changes in weather, ecology, and hours of daylight.

Seasons result from the yearly revolution of the Earth around the Sun and the tilt of the Earth's axis relative to the plane of revolution.

The seasons are marked by solstices and equinoxes — astronomical terms that relate to Earth’s tilt. The solstices mark the points at which the poles are tilted at their maximum toward or away from the sun. This is when the difference between the daylight hours and the nighttime hours is most acute.

The solstices occur each year on June 20 or 21 and Dec. 21 or 22, and represent the official start of the summer and winter seasons. The vernal equinox and autumnal equinox herald the beginning of spring and fall, respectively. At these times of the year, the sun appears to be directly over Earth’s equator, and the lengths of the day and the night are equal over most of the planet.

On March 20 or 21 of each year, the Northern Hemisphere reaches the vernal equinox and enjoys the signs of spring. At the same time, the winds turn colder in the Southern Hemisphere as the autumnal equinox sets in. The year's other equinox occurs on Sept. 22 or 23, when summer fades to fall in the north, and winter’s chill starts giving way to spring in the south.

In temperate and subpolar regions generally four calendar based seasons are recognized: spring, summer, autumn, and winter.

In India, and in the Hindu calendar, there are six seasons or Ritu : Hemant (pre-winter), Shishira (Winter), Vasanta (Spring), Greeshma (Summer), Varsha (Rainy) and Sharad (Autumn). But according to the modern climatic studies India has only three predominant seasons they are summer season, rainy season and winter season. The summer months lasts from about March to June, the rainy season stretches form June to October and the winter season remains in India from November to March. Various climatic factors are responsible for the seasonal changes in India. The monsoon season is pretty fervent in India with heavy clouds drenching most parts of India. The summer season is pretty hectic too with India being a tropical country most parts of India are scorched with sweltering heat. The Indian winter is usually mild and enjoyable in comparison to the other temperate countries of the world.