Petrichor: Yes, there is a word for the scent of rain.

pet·ri·chor

ˈpeˌtrīkôr/

noun

1. a pleasant smell that frequently accompanies the first rain after a long period of warm, dry weather.

"other than the petrichor emanating from the rapidly drying grass, there was not a trace of evidence that it had rained at all"

Petrichor is derived from two Greek words; πέτρα, petra meaning “stone,” and ιχώρ, ichor meaning “the juice, not blood, that flows in the veins of gods.” The word was created in 1964 by two Australian researchers, Isabel Joy Bear and Richard G. Thomas, for their article in the journal Nature called,"Nature of argillaceous odour."

The science behind petrichor I will leave to the reader to explore. The simplified explanation is that the scent occurs when humidity increases prior to rainfall, filling the pores of stones and soil with particles of water causing the surface oils to be released into the air. As the rain increases, so does this process, and the petrichor is disbursed by the wind. Petrichor can be more readily detected when a rainfall follows a dry spell.

For etymology junkies, see definitions below of πέτρα, petra and ιχώρ, ichor from Liddell and Scott’s Greek-English Lexicon.

πέτρα, Ion. and Ep. πέτρη, ἡ, rock; freq. of cliffs, ledges, etc. by the sea, λισσὴ αἰπεῖά τε εἰς ἅλα πέτρη Od.3.293, cf. 4.501, etc.; χῶρος λεῖος πετράων free from rocks, of a beach, 5.443; (2-4 omitted)

ἰχώρ [ῑ], ῶρος, ὁ, ichor, the juice, not blood, that flows in the veins of gods, Il.5.340,etc.: Ep.acc. ἰχῶ ib.416: in pl., of the Giants, Str. 6.3.5; later simply, blood, A.Ag.1480 (anap.).