Measuring Temperature:
1. The temperature of a unit volume of air at a given time is measured in scales like Celsius, Fahrenheit, and Kelvin. Meteorologist measures the temperature by the Thermometer, Stevenson screen and minimum and maximum Thermometer.
2. The energy received by the earth through insolation is lost by outgoing radiation.
3. Atmosphere is mainly heated by outgoing radiation from 2 to 4pm .So the maximum temperature is recorded between 2 and 4 pm regularly and minimum temperature is recorded around 4 am before sunrise.
Mean Temperature:
1. The average of maximum and minimum temperatures within 24 hours is called mean daily temperature [(87°F + 73°F)/2=80°F].
2. Diurnal range of temperature is the difference between the maximum and minimum temperatures of a day. Annual range of temperature is the difference between the highest and lowest mean monthly temperatures of a year.