The US have all types of land. I have region that is with ocean and some region that is far away from ocean. Some landscapes are mountainous and some are plain. The US have all types of weathers. Weather does not only effect people but also effects economy, agriculture, energy use, water resources, transportation, and industry. Weather changes constantly while climate is the average weather. Air composition varies from place to place. Oxygen and nitrogen makes 99% ofvolume of clean, dry air. CO2 is only 0.04% and it is efficient absorber of energy so it have effecton heating of atmosphere. Plants and ocean absorbs some quantity of carbon dioxide but 45% remains in air. Water vapor, dust particles, and ozone changes in air from one place to another place. Like carbon dioxide, water vapors also absorb heat. Solid and liquid particles like smoke and soot from fires, pollen and microorganisms, soil are called aerosols. Like CO2 and water vapors, another important component of atmosphere is ozone. But it is present in very less amount. Ozone is useful for us because it absorbs ultraviolent radiation those are dangerous for us. Atmospheric pressure is the pressure that air exerts above it and at sea level it is 1000 millibars but it decreases at heights. There are four layers of atmosphere according to temperature. First one is Troposphere. It is the layer where we live and its temperature decreases with height and the boundary of troposphere iscalled tropopause. The 2nd type is stratosphere and in this layer temperature remains same up to 20 km and then increases until tropopause. The third layer is mesosphere and its temperature decreases and becomes constant at the height of 80 km. the last layer is thermosphere and its temperature increases. The energy by which temperature changes is come from sun. The variation in weather is due to the factors that when sun is directly above earth then earth receive more heat. Heat and temperature are closely related to each other. There are three mechanism of heat transfer. Conduction which transfer heat by molecular activity, convection is by mass movement and last one is radiation. When ration strikes an object then three different results occur. First one is that energy is absorb by object, second object like water transmit the energy and third is that the object bounce off the heat. I have studied that temperature not only varies from place to place and from time to time but humans also have effect on temperature. When the level of CO2 rises then temperature increases. Use of air conditioners damages ozone layer and in this way temperature on earth increases.Temperature is recorded constantly in weather stations. Highest, lowest and mean temperature ondaily, weekly, monthly and yearly basis is recorded in weather stations. The receiving of solar variation is a main factor of temperature variation bit other factors like sun angle and length of day are the function of latitude and control temperature variations. But latitude is not only factorsbecause the areas with same latitude also have different temperature. Differential heating of land and water, altitude, geographic position, and ocean currents also plays an important role in temperature variation. On maps isotherms are towards east-west and shows the decrease in temperature poleward from the tropic. Isotherms are deflected polewards due to warm currents while equatorward bending is caused by the cold currents.I have learned that temperature is not same everywhere. Temperature variation depends upon latitude, geographic position, and ocean currents. Difference of temperature can be useful for the country because people from warm areas move toward cold areas during summer area and in thesame way people from cold areas move towards warm land in winter for recreational tours and for other purposes and in this way country economy can be boosted. We should be aware of the danger of high temperature causes by the depletion of ozone layer due to the use of air conditioners, increase in the quantity of carbon dioxide and consumption of fuels. We should try to use natural energy instead of fuel energy.I have a question for you that what should we do to save ourselves from intense heat or from intense