Petrichor

Petrichor is the special smell you notice when it starts raining after a long, dry spell. This smell comes from a mix of different things, including the dirt and rocks on the ground and the oils from plants around you.

When it's been really dry for a while, the ground gets thirsty and starts to suck up any moisture in the air. During a hot summer, plants try to conserve water by releasing oils into the air to prevent dehydration. These oils mix with any other compounds in the air and stick to things like rocks, soil, and pavement.

When it finally rains, drops of water mix with these oils and other compounds and they all start to evaporate into the air. As the smell wafts towards your nose, you know it's raining and the earth is getting the water it needs.

So, next time it rains after a long drought, just take a deep breath and enjoy that fresh, earthy, petrichor smell!