Notes On Weather and Climate - CBSE Class 7 Geography
Weather is the day-to-day and hour-to-hour condition of the atmosphere. Climate on the contrary is the average condition of the weather in any area from a long time period like 25 years or so. Temperature is the degree of coldness or hotness of the air. Summers are hotter than winters, this means that the temperature in summers is high as compared to the winters. Insolation is the measure of solar energy received by the earth’s surface in a given time. The amount of solar energy trapped decreases when we move towards the poles away from the equator. This is the reason why temperature also decreases at poles and they remain frozen.  The temperature in cities is comparatively higher than in villages. This is because of the concrete and metal used in the buildings and the asphalt in the roads in the cities get hot during the day. The high-rise and crowded buildings in the cities also trap warm air, thereby raising the temperature. Degree Celsius was invented by Anders Celsius and is the standard unit to measure the temperature. As per Celsius scale, the freezing point of water is Zero degree and the boiling point is 100 degree Celsius. The air above exerts great pressure on us, but we do not feel the pressure owing to the pressure exerted by our body. The pressure exerted by the air on the earth’s surface is called air pressure and it is the highest at the lowest level of the earth’s surface i.e. sea level and decreases as we move up. The air pressure is distributed on the basis of the temperature of air at a particular place. The area which has high temperature will have a low pressure as the air gets heated and rises and vice-versa. The movement of air from a high pressure area to a low pressure area is called wind. Winds are classified into three types i.e. seasonal winds, permanent winds and local winds. Winds that blow throughout the year are called as permanent winds like the trade winds, easterlies and westerlies. Seasonal winds are the winds which change their direction as per the seasons like the monsoon winds in India, which blow only during the monsoon season. Local winds are like the sea breeze and land breeze. In day time, the wind blows from the sea which has a high air pressure owing to the low temperature, hence is called sea breeze. Whereas, during night, land is cooler and the air pressure is high, hence the winds blow from land to sea called the land breeze. Loo is another form of local wind, which is dry hot air that blows during the summers in the northern plains and the western parts of India.

#### Summary

Weather is the day-to-day and hour-to-hour condition of the atmosphere. Climate on the contrary is the average condition of the weather in any area from a long time period like 25 years or so. Temperature is the degree of coldness or hotness of the air. Summers are hotter than winters, this means that the temperature in summers is high as compared to the winters. Insolation is the measure of solar energy received by the earth’s surface in a given time. The amount of solar energy trapped decreases when we move towards the poles away from the equator. This is the reason why temperature also decreases at poles and they remain frozen.  The temperature in cities is comparatively higher than in villages. This is because of the concrete and metal used in the buildings and the asphalt in the roads in the cities get hot during the day. The high-rise and crowded buildings in the cities also trap warm air, thereby raising the temperature. Degree Celsius was invented by Anders Celsius and is the standard unit to measure the temperature. As per Celsius scale, the freezing point of water is Zero degree and the boiling point is 100 degree Celsius. The air above exerts great pressure on us, but we do not feel the pressure owing to the pressure exerted by our body. The pressure exerted by the air on the earth’s surface is called air pressure and it is the highest at the lowest level of the earth’s surface i.e. sea level and decreases as we move up. The air pressure is distributed on the basis of the temperature of air at a particular place. The area which has high temperature will have a low pressure as the air gets heated and rises and vice-versa. The movement of air from a high pressure area to a low pressure area is called wind. Winds are classified into three types i.e. seasonal winds, permanent winds and local winds. Winds that blow throughout the year are called as permanent winds like the trade winds, easterlies and westerlies. Seasonal winds are the winds which change their direction as per the seasons like the monsoon winds in India, which blow only during the monsoon season. Local winds are like the sea breeze and land breeze. In day time, the wind blows from the sea which has a high air pressure owing to the low temperature, hence is called sea breeze. Whereas, during night, land is cooler and the air pressure is high, hence the winds blow from land to sea called the land breeze. Loo is another form of local wind, which is dry hot air that blows during the summers in the northern plains and the western parts of India.

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