The climate is always for a large area like a country or a big region and generally it does not change, like India has monsoon climate whereas weather is always for a smaller area like that of a city or village where it may frequently change like raining in the morning and sunny in the afternoon.
Climate refers to the sum total of weather conditions and variations over large area for a long period of time (more than 30 years). Weather is state of atmosphere over an area at any point of time. Similarly, weather conditions which last for longer duration are responsible for making a season.
The places which are closer to equator have high temperature. As one moves towards the poles temperature decreases. India is located in Northern hemisphere closer to equator at 8°4' and 23½° Tropic of Cancer passes through the central part of India. So, in south of this latitude we find tropical climate and towards the north we find sub-tropical climate.
For example, Andhra Pradesh would be hotter than Haryana. Parts lying south of the Tropic of Cancer receive more solar heat than those lying north of it.
2. Distance from the sea
The southern half of India is surrounded by sea from three sides: the Arabian Sea in the west, the Bay of Bengal in the east and the Indian Ocean in the south. Due to moderating influence of the sea this region is neither hot in summer nor very cold in winter.
For example the area of North India which is far away from the sea has extreme type of climate and the area of south India which is nearer to the sea has equable type of climate.
It means the height above the average sea level. The atmosphere becomes less dense and we feel breathlessness as we go higher from the earth surface and thus the temperature also decreases with the height.
For example, the cities located on the hills are cooler like Shimla whereas the cities lying in the plains have hot climate like Ludhiana.
4. Mountain Ranges
The Himalaya Mountain is located in the northern part of our country with an average height of 6000 m. It protects India from cold winds of Central Asia. On the other hand, they check rain bearing South-West Monsoon winds and compel them to shed their moisture in India.
Similarly, Western Ghats force rain bearing winds to cause heavy rain fall on the Western slopes of the Western Ghats.
5. Direction of surface winds
The wind system also affects the Indian climate. This system consists of monsoon winds, land and sea breeze, and local winds.
In winter the winds blow from land to sea so they are cold and dry. On the other hand, in summer wind blow from sea to land bringing the moisture along with them from the sea and they cause wide spread rain in most part of the country.
6. Upper air Currents
Besides surface winds, there are strong air currents called Jet streams which also influence the climate of India. These jet streams are a narrow belt of fast blowing winds located generally at 12,000 metre height above the sea level.
They bring western cyclonic disturbances along with them. These cyclonic winds originate near the Mediterranean Sea and move eastwards. On their way, they collect moisture from Persian Gulf and shed it in the North western part of India during winter seasons. These Jet streams shift northwards during summer season and blow in Central Asia. Thus helps in the onset of monsoons.