What is Diurnal Variation Of Atmospheric Temperature?

The temperatures of the atmosphere and the surface show a systematic change during an average 24 hour period (per day) which is termed the diurnal variation of temperature. For both land and sea, minimum and maximum surface temperatures are generally attained at sunrise and midday respectively, and the minimum and maximum air temperatures at about half hour after sunrise and 1500 LMT whereas in the winters the maximum air temperature occurs at 1400 LMT.