Temperature is the measure of how cold or hot somewhere is. Temperature is usually higher during the day than at night. Rural areas (the countryside) are often cooler than towns and cities. This is because there are more buildings and factories ( known as 'heat islands') which absorb heat during the day, releasing it slowly at night and warming the surrounding air.
Temperature is measured using a thermometer, with units in degrees on Fahrenheit (ºF) or Celcius (ºC) scales. The main type of thermometer used is the liquid-in-glass thermometer. A liquid (usually alcohol) expands depending on temperature. It then moves up a small tube alongside a scale, from which temperature readings can be made.