Temperature drops throughout the night because of two processes. First, the Earth's radiation balance at the surface becomes negative after sunset . Thus, the surface of the Earth stops heating up as solar radiation is not being absorbed. Secondly, conduction and convection transport heat energy up into the atmosphere and the warm air that was at the surface is replaced by cooler air from above because of atmospheric mixing. Temperature begins rising as soon as the net radiation budget of the surface becomes positive.
Temperature continues to rise from sunrise until sometime after solar noon.
After this time, mixing of the Earth's surface by convection causes the surface to cool despite the positive addition of radiation and heat energy . As the Earth revolves around the sun, locations on the surface may under go seasonal changes in air temperature because of annual variations in the intensity of net radiation . Variations in net radiation are primarily controlled by changes in the intensity and duration of received solar insolation which are driven by variations in daylength and angle of incidence. Monthly variations in net radiation and average monthly temperature for Manaus, Brazil. At Manaus , values of monthly net radiation average about 135 Watts per square meter.