Introduction

Introduction 
    Weather is the day to day changes in our atmosphere in terns of temperature, moisture, wind, sun, cloud, rainfall and atmospheric pressure Weather conditions vary from place to place. Perhaps it is hot and rainy where you live but at the same time in other        parts of the world it could be cloudy and rainy or may be snowing. Weather changes in a short span of time. It may be bright and sunny in the morning, and cloudy in the afternoon. Thus, weather is the atmospheric condition in a particular area over a short          period of time.
    Climate refers to the weather conditions prevalent over a large area for a long period of time (say 25 years). 

Factors influencing climate
    Latitudes: The climate of a place depends upon its location on the earth. Places on the earth which are near to the equator are hot because here the sun's rays fall vertically. They are said to have a tropical climate. Places in the polar regions are cold                because the sun's rays fall at a slanting angle.
    Height above sea level : The temperature decreases with increase in altitude. For every 1, 000 metres of ascent there is a drop in temperature of 6°C. This is known as the Lapse Rate.
    Relief features :  Himalayas in the north and the seas surrounding the peninsula have played a major role in influencing the climate of India. The Himalayas prevent the cold winds from the Tibetan plateau to enter India. The mountain slope facing the rain-        bearing clouds receive rain and is called the windward side. The other side is the leeward side and receives less rainfall. This is the reason that Mumbai being on the windward side receives higher rainfall, and Pune being on the leeward side receives less          rainfall.
    Distance from the sea : Places near the sea receive cool breeze. This makes the climate pleasant and equable. It is neither too hot nor too cold in the coastal areas. The coastal areas are also humid. Humidity is the amount of water vapour contained in a        given volume of air.
    In places away from the sea, summers are very hot and winters are very cold. This kind of climate is called extreme climate and it is found in deserts.

Formation of Cyclones
    In October and November there is a gap between the rainy season and winter. It is during this season that cyclones form over. A cyclone is a huge storm that originates at sea in the tropical zone. It is characterized by a large low pressure centre and               strong winds spiraling inward and upward. The coastline of India is vulnerable to cyclones, particularly the east coast. Cyclones in this area may come in the months of April–May or October–December. These cyclones are very destructive as they bring           high speed winds and heavy rainfall in the densely populated deltaic regions of the Godavari, Krishna and Caveri.

Distribution of Rainfall
    Monsoon winds are irregular and not punctual. These winds can cause floods in one part and drought in another part simultaneously. Cherrapunji and Mawsynram in Meghalaya have more than 800 cm of annual rainfall, and places like Jaisalmer in               Rajasthan receive rainfall less than 12 cm, The western coastal plains and the north-east region receive more than 200 cm of rainfall while Gujarat, Rajasthan, Punjab and Haryana bordering it receive rainfall less than 60 cm. The Deccan Plateau also             receives less rainfall. Tamil Nadu receive less rainfall from the south-west monsoon winds. November and January is the rainy season here. On an average the country receives an annual rainfall of 120 cm.