[title650.gif] HOMEPAGE : Guestbook : Tonbridge history Science index Day and Night Day and Night World Map Day Length Longtitude Latitude The Equator The Prime Meridian Line International Date Line Why do we have Seasons? Equinox Solstice Sunrise and Sunset project Why do we have a year? The Moon Interactive Science activities Homework Help Why do we have Seasons? seasons In the UK we have four seasons: * Spring - March to May * Summer - June to August * Autumn - September to November * Winter - December to February Average temperature each seasons in the UK The Reason for the Seasons Many people think that some parts of the year are hotter because we're nearer to the Sun, but the real reason is that the Earth is wonky (tilted). [righttilt.jpg] Why do we have seasons? We have seasons because the earth is tilted (wonky) as it makes its yearly journey around the sun. The Earth's tilt The Earth's axis is tilted at an angle of 23.5 degrees. This means that the Earth is always "pointing" to one side as it goes around the Sun. So, sometimes the Sun is in the direction that the Earth is pointing, but not at other times. The varying amounts of sunlight around the Earth during the year, creates the seasons. The tilt of the Earth's AXIS is the most important reason why seasons occur. We have hot summers and cold winters because of the tilt of the Earth's axis. The tilt of the Earth means the Earth will lean towards the Sun (Summer) or lean away from the Sun (Winter) 6 months later. In between these, Spring and Autumn will occur. Important Facts * The Earth revolves around the Sun. * The North pole always points the same way as the Earth revolves around the Sun. * The Earth's movement around the sun causes the seasons. During a Year The Earth takes 365.24 days to orbit the sun. As we move around the Sun during the year, the amount of light each area of the planet receives varies in length. When the Earth's axis points towards the Sun, it is summer for that hemisphere. When the Earth's axis points away, winter can be expected. ------------------------------------------- The north pole tilts towards the sun [righttilt.jpg] sun summer It is Summer time in countries in the Northern Hemisphere. [snow.gif] It is Winter time in countries in the Southern Hemisphere. ------------------------------------------- The north pole tilts away from the sun sun [righttilt.jpg] [snow.gif] It is Winter time in countries in the Northern Hemisphere. summer It is Summer time in countries in the Southern Hemisphere. ------------------------------------------- Since the tilt of the axis is 23 1/2 degrees, the north pole never points directly at the Sun. Autumn The north pole begins to move away from the Sun. The Sun rises lower in the sky so the days start getting shorter. When the Sun is at its mid-point in the sky, we reach the 'autumn equinox', around 22 September. Day and night are both 12 hours long and its the beginning of autumn. Spring The Earth continues on its path, and our north pole starts moving towards the Sun again. The Sun moves upwards in our skies and the days continue getting longer. Again, we reach a midpoint when day and night are both 12 hours long. This is called the 'vernal (or spring) equinox' and happens around 21 March. Did you know? The Earth's movement around the sun causes the seasons, but it does not affect the temperatures during the seasons. Many people believe that the temperature changes because the Earth is closer to the sun in summer and farther from the sun in winter. In fact, the Earth is farthest from the sun in July and is closest to the sun at the beginning of January! The height of the sun in the sky varies with the seasons. The sun is at its heighest at 12:00pm (noon) on any gven day. In the summer the sun is higher than it is in the other three seasons. Summer Summer During the summer, the sun's rays hit the Earth at a steep angle because the sun is higher in the sky. The light does not spread out very much, thus increasing the amount of energy hitting any given spot. The long daylight hours during the summer months allow the Earth plenty of time to reach warm temperatures. This is why the days are hotter in the summer months. Because the sun is higher in the sky our shadows are shorter than they are in the the other three seasons. Winter Winter During the winter, the sun's rays hit the Earth at a shallow angle because the sun is lower in the sky. These rays are more spread out, which minimizes the amount of energy that hits any given spot. The long nights and short days prevent the Earth from warming up. This is why we have cold winters. The Length of the day and night varies throughout the year Summer Months Summer is warmer and winter is colder because of the length of our days and nights. In the summer daylight lasts longer and night time is shorter. Winter Months In winter the days are shorter and the nights longer.There is more time for the sun to warm us during long summer days. And short winter days have long, cold nights. The three reasons why we have Seasons 1. Tilt 2. Revolution - The Earth revolves around the Sun. 3. The North Pole always POINTS in the Same Direction Watch a video of why we have seasons www.teachertube.com Equinox previous page next page Day and Nght Average temperature each seasons in the UK spacer back to the top [literacy.gif] [maths.gif] [science.gif] Interactive Literacy Interactive Maths Interactive Science About Us | Search | Site Map | Feedback | User Information | Contact Us © Copyright Mandy Barrow Terms & Conditions Woodlands Junior School, Hunt Road Tonbridge Kent TN10 4BB UK