Snipfact:

  Galileo invented the thermsocope, a form of thermometer. Later, sealed thermometers using mercury, which expands in a narrow tube as the temperature rises, were developed. Gabriel Fahrenheit’s scale dates from 1714, and that of Anders Celsius from 1742. The maximum and minimum thermometer, which records the highest and lowest temperatures reached over a period of time, was invented by James Six a Cambridge in 1780.

    Rain gauges – containers that measure the amount of rain that has fallen – date from ancient China and India. In 1662, British architect Sir Christopher wren invented a tipping bucket rain gauge, which emptied itself when full.

    Wind speed is measured by a cup anemometer. This has three or four cups that rotate round a vertical rod. The speed at which the wind spins the cups round is recorded by a counter. A Wind vane shows the direction of wind, and an anemograph records the speed on a chart.

    Weather forecasters use a range of instruments. Balloons, radar stations and orbiting satellites also provide increasingly accurate weather information, and computer programs are able to make detailed forecasts.

    Tornados, or twisters, are columns of air that spin violently, reaching speeds of over 420 km/h. They destroy  crops and any houses or vehicles in their path. Tornadoes are rare in the UK, but one struck Kensel Rise, London, on 7 December 2006, damaging houses and cars. In the book and film of The Wizard of Oz (1939) Dorothy is carried by a tornado from her Kansas home to the magical land of Oz.

  The hottest place where people live is Djibouti, in the Republic of Djibouti, Africa. The average temperature is 30 o C. Next hottest are Timbuktu in Mali and Tirunelveli in India, both 29.3 o C. The coldest place where people live in Norilsk, Russia, with an average temperature of –10.9 o C. Next coldest is Yakutsk in Rusiia, at  -10.1 o C.

    There are ten types of clouds. Each has a characteristic shape and appears at certain levels in the sky. Altocumulus 2,000-7,000 m Cirrocumulus 5,000-13,500 m Cirrus 5,000-13,500 m Cirrostratus 5,000-13,500 m Altostratus 2,000-7,000 m Nimbostratus 900-3,000 m Cumulus 450-2,000 m Stratocumulus 450-2,000 m Cumulonimbus 450-2,000 m Stratus below 450 m  

    The Beaufort scale was introduced in 1806 by British Admiral Sir Francis Beaufort (1774- 1857) to describe wind effects on a fully rigged man-of-war ship. It was later extended to describe how winds affect land features such as trees. The Beaufort scale is divided into values from 0 for calm winds to 12 and above for hurricanes. Forecasters often describe winds by their force number – for example, a force 10 gale. Wind speed can also be measured in knots: 1knot = 1.85 km/h. 0 Calm : 0-2 km/h 1 Light air : 3-6km/h 2 Slight breeze : 7-11 km/h 3 Gentle breeze : 12-19 km/h 4 Moderate breeze : 20-28 km/h 5 Fresh breeze : 29-38 km/h 6 Strong breeze : 39-49 km/h 7 High wind : 50-61 km/h 8 Gale : 62-74 km/h 9 Strong gale : 75-88 km/h 10 Whole gale : 89-102 km/h 11 Storm : 103-117 km/h 12 Hurricane: 118 km/h +