Diurnal variation of surface air temperature

During the day, variations in temperature they are much less marked on the sea than on land. The diurnal variation of the sea water temperature at the surface is generally less than one degree and, therefore, the air temperature near the sea surface has little variation when it is calm.

In contrast, for desert regions located in the interior of the continents, the air temperature can vary by up to 20 degrees between day and night. Near the coasts, this variation in temperature depends a lot on the direction of the wind: the amplitude of the variation is very marked if the wind comes from land, but it is weaker if the wind comes from the sea. Local land and sea breezes too tend to attenuate the diurnal temperature range.

As a general rule, when there is calm, the diurnal variation in surface air temperature is more marked. If there is wind, the air is moved in a very great thickness, therefore the diurnal temperature range can decrease. CloudinessOn the other hand, it reduces the amplitude of the diurnal variation in temperature by reflecting the sun's radiation and not reaching the earth's surface, while at night the clouds act as a "cover" for the surface to cool down.

Surface temperature variation is also influenced by the nature of the earth's surface and the thermal conductivity of the underlying layer. Likewise, the nature of the surrounding terrain is important, since the temperature of a given place can be modified by the flow of hot air or cold air that comes from the surrounding areas.

La environmental influence surrounding is evident in large cities. On clear and calm nights, the temperatures recorded in the city center can exceed by S * C those observed near open land. During the day, temperatures are also influenced by the heat given off by the city's buildings and by all kinds of activities that take place there.

More information - The relationship between heat and temperature