Rain dust

The leaves of this Schefflera show the dust stains of a rain dust (near Paris, France)

Rain dust or snow dust, traditionally known as muddy rain, red rain, or coloured rain, is a variety of rain (or any other form of precipitation) which contains enough desert dust for the dust to be visible without using a microscope.


The rain dust phenomenon was studied by Italian scientist Giuseppe Maria Giovene (1753–1837), who managed to correctly explain the phenomenon as early as 1803. On 7 March 1803, rain dust fell over South Italy's region Apulia. At that time, people believed that the rain was caused by the explosions of Italy's volcanoes Mount Vesuvius or Etna, or that it was due to the transport of matter coming from the sea floor and raised by vapor. Giuseppe Maria Giovene brilliantly managed to relate the phenomenon to the wind which occurred prior to the rain event, and he came to the conclusion that the sand had come from Africa and that it had been pushed by the wind coming from south-east.[1][2]

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