what does petrichor mean?

ditch the umbrella next time it rains!

Petrichor is the earthy, pleasant scent that arises when rain hits dry soil. 

The term was coined in 1964 by two Australian researchers, Isabel Joy Bear and R.G. Thomas, they discovered that the smell comes from a combination of oils produced by plants during dry periods and a compound called ‘geosmin,’ which is released by soil-dwelling bacteria called actinomycetes.

When rain hits the ground, these oils and geosmin are released into the air, creating the familiar and refreshing smell of rain after a dry spell.