Black rain fell in Switzerland on Jan. 20, 1911. According to Nature, 85-451, “in certain conditions of weather, snow may take on an appearance of blackness that is quite deceptive.” Fort comments: “May be so. Or at night, if dark enough, snow may look black. This is simply denying that a black rain fell in Switzerland, Jan. 20, 1911.”
–Charles Fort, The Book of the Damned, p.28 (The Complete Books of Charles Fort, Dover, c1974).