How to Avoid Bad Weather, 1660

Edward Topsell, The History of Four-Footed Beasts and Serpents (1658)

"Whosoever are defended by a skin of a River Horse called Hippotamus, are never touched by the Thunder... some say that if you hold a Looking-Glass against the Cloud that hangs over you, the Hayl will pass away:  also if you compass the place with the skin of an Hyæna, Crocodile, or Sea Calf, and hang the same up before the Doors of your house, for then the Hail will not fall." 

Johann Jacob Wecker, Eighteen Books of the Secrets of Art & Nature

Added bonus: nothing says "welcome!" like a crocodile skin nailed to your front door.

How to Predict Rain, c. 300 BC

"Nonaquatic birds bathing themselves are a sign of rain or storm. And a toad washing itself and frogs croaking more than usual signal rain. Likewise the appearance of the lizard which they call "salamander"; and furthermore a green frog singing in a tree signals rain... Likewise, if a tame duck makes its way under the cornice of a house and flaps its wings, this signals rain... If a cooking vessel filled to the brim emits sparks all over it is a sign of rain. Centipedes in large numbers creeping towards the wall are a sign of rain." 

Theophrastus of Eresus, On Weather Signs (c. 300 BC)

Just face it: it's going to rain. (Also, centipedes in large numbers creeping towards the wall are a sign that you should call an exterminator.)