What is the mechanism by which the temperature *rises* when clouds come
over on otherwise clear nights*?

Common sense suggests that the most they could do would be to halt the
drop in temperature. After all, a rise in temperature *should* require a
heat source, and those are absent at night.

*I'm referring to nights with no frontal activity, of course.
--
Paul Hyett, Cheltenham (change 'invalid83261' to 'blueyonder' to email me)