Expertlatin
Roughly, pluvia is the wet stuff itself, the falling water that comprises the shower, imber. More or less as you would in English, it's quite legitimate to use either, as you wish, to describe the actual weather. Imber, however, does tend to mean heavy or cold rain, rather than a gentle, soft shower.
What does Pluvia mean?
Noun. pluvia f (plural pluvias) rain. shower (precipitation)
What is imber in latin?
Noun. imber m (genitive imbris); third declension. rain quotations ▼ a storm.
