Radiant cooling occurs in winter on cloudless nights.
That’s what causes frost.You can also feel at other times
to a lesser degree.
Living in the desert, with below normal surface humidity being the norm, I have noticed that when upper atmospheric humidity is high, through polarized lenses, the sky looks gray, but when upper level atmospheric humidity is low, during the day, again through polarized lenses, the sky looks black.
This matters, because without that humidity, the daytime surface temperature is hot, but at night the heat quickly radiates away, and the desert becomes bone chilling cold.