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www.GOALias.blogspot.comDateMaximumtemperature03-08-06 26.0°C04-08-06 23.5°C05-08-06 25.0°C06-08-06 22.0°C07-08-06 25.5°C08-08-06 23.3°C09-08-06 24.4°CFig. 7.2 Graph showing the variation of maximum temperature during 03 to 09 August 2006As it is clear from any weather report,the maximum and minimumtemperatures are recorded every day. Doyou know how these temperatures arerecorded. In Chapter 4 you have learntI wonder why weatherchanges so frequently!What is the source of weatherin the first place?that there are special thermometers forthis purpose, called maximum andminimum thermometers. Can youguess when during the day we have themaximum temperature and when theminimum?The maximum temperature of the dayoccurs generally in the afternoon whilethe minimum temperature occursgenerally in the early morning. Can younow understand why in summers we feelso miserable in the afternoon andcomparatively comfortable early in themorning?All changes in the weather are caused by the sun. The sun is a huge sphere ofhot gases at a very high temperature. The distance of the sun from us is verylarge. Even then the energy sent out by the sun is so huge that it is the source ofall heat and light on the earth. So, the sun is the primary source of energy thatcauses changes in the weather. Energy absorbed and reflected by the earth’ssurface, oceans and the atmosphere play important roles in determining theweather at any place. If you live near the sea, you would have realised that theweather at your place is different from that of a place in a desert, or near a mountain.70SCIENCE