In July 1955, residents of Cincinnati, Ohio (USA) reported red rain. It burned to the
touch and left plants dead and shriveled. The unusual hue of this dangerous rain has
never been explained, but it turns out that colored rain is actually more common than
one would believe. Impurities or natural substances present in the air usually cause
this phenomenon. Yellow and green rainrain occurs in places where pollen is very thick.
A black rain that fell over England in 1884 came from atmospheric soot. Red rain falling
in Europe and over the Caribbean can be traced to red desert sand blown into the air
from the Sahara.