Highest occurrence of red rain

Coloured rain, particularly red rain, had been observed to fall in the Indian state of Kerala, on the Malabar coast, since 1896. From 25 July to 23 September 2001 Kerala experienced multiple showers of red rain, making the region the first and only place on Earth where it has occurred on three consecutive months. Explanations for the phenomenon range from suspended dust to extra-terrestrial spores but, in 2015, scientists released their analysis of red rain samples and concluded that it was because of the presence of microalgae spores from the species Trentepohlia annulata.

Red rain was mentioned in Homer’s Iliad, written c. 1260–1180 BCE.

Red rain has also fallen in Kerala in 2012 and 2013.