NCERT Chapter Summary: Climate
Climate refers to the sum total of weather conditions and variations over a large area for a long period of time (more than thirty years). Weather refers to the state of the atmosphere over an area at any point of time. The elements of weather and climate are the same - temperature, atmospheric pressure, wind, humidity and precipitation.
The weather conditions fluctuate very often even within a day. But there is some common pattern over a few weeks or months, i.e. days are cool or hot, windy or calm, cloudy or bright, and wet or dry. On the basis of the generalised monthly atmospheric conditions, the year is divided into seasons such as winter, summer or rainy seasons.
The climate of India is described as the monsoon type. In Asia, this type of climate is found mainly in the south and the southeast. Despite an overall unity in the general pattern, there are perceptible regional variations in climatic conditions within the country.
There are six major controls of the climate of any place - latitude, altitude, pressure and wind system, distance from the sea (continentality), ocean currents and relief features.
The monsoon type of climate is characterised by a distinct seasonal pattern. The weather conditions greatly change from one season to the other. Four main seasons can be identified in India:
- Cold weather season
- Hot weather season
- Advancing monsoon
- Retreating monsoon