Number of seasons and their name?

Answer 1

There are four calendar based seasons and six ecological seasons that are recognized in the temperate regions of the world.

The calendar seasons in the northern hemisphere are spring (March, April, May), summer (June, July, August), fall (September, October, November), and winter (December, January, February).

The ecological seasons are not strictly calendar based but are defined by local plant and animal activity. Nevertheless they can be roughly dated for the northern hemisphere as prevernal (pre-spring: February/March to March/April), vernal (spring: March/April to June), estival (high summer: June to August), serotinal (late summer: August to September), autumnal (fall: September to November/December), and hibernal (winter: November/December to February/March). In mild temperate climates, the hibernal season starts later and ends earlier than in cool temperate zones. The prevernal and vernal seasons start earlier in mild temperate climates.

In the Southern Hemisphere, the dates are reversed by six months for both the calendar and ecological seasons.

Source: Wikipedia

Answer 2

It varies across the world. In most temperate countries there are four seasons: winter, spring, summer and autumn (or fall).

In many tropical countries, there are three seasons: winter, summer and monsoon. Nature does not "go to sleep" in the autumn since the winters are not as harsh, and consequently, spring is not as big a transformation.