Of the total radiation  that leaves the Earth...
Just to recap, we've looked at several parts of Earth's radiation budget.
We said the global budget is balanced because if it weren't, temperatures would be rising or dropping, but instead they're quite constant.
We looked in detail at the portion of the budget that entered into the atmosphere. We said incoming radiation is either transmitted, scattered, or absorbed/reradiated.
Then we looked at the portion of the budget just at Earth's surface. (Remember that some of the incoming radiation does not make it to the ground but is either reflected into space or absorbed in the atmosphere.) Of the portion that reaches the ground, a little is reflected and the rest is either absorbed/reradiated or taken up in non-radiative processes.
Lastly (today), we looked at the total outgoing budget and saw that nearly half of the outgoing energy comes from reradiation, one-third from reflection, and one-fourth from non-radiative energy transfer.
Things to note:
Putting these two facts together means that at some times of the day, more energy will be leaving than entering. At other times, more will be entering than leaving.
When the incoming energy is less than the outgoing energy, the temperature will drop. This is true to the left and right of the two vertical dashed lines in the plot. When the incoming energy is greater than the outgoing energy, the temperature will rise. This is true in the center of the plot between the two vertical dashed lines.
Notice that the greatest amount of incoming radiation doesn't occur at the same time as the highest temperature. There is a "time lag" between the peaks. However, the time lag does not occur because heating is slow. Rather, temperature will keep going up as long as the sun pumps in more energy than the Earth puts out. The highest temperature is at the point when the Earth starts putting out more energy than the sun puts in. That marks the onset of falling temperatures.
If you replace the time axis with months of the year instead of hours of the day, you get a similar pattern. There is also a "time lag" in the yearly patterns (remember that we get the most sun on June 22, the summer solstice, but the hottest months are after that).
overhead: net radiation
This showed net radiation at ground level. All wavelengths of radiation are included in the term "net radiation." The term "net radiation" takes into account all energy transfers except the non-radiative energy processes (latent heat, sensible heat). The maximum net radiation was at low latitudes and the minimum was at high latitudes.
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