The weather rock or weather stone is a humor display that pokes fun at the intricate technology used in modern weather forecasts, as well as the fact that their accuracy is less than perfect. A rock is typically hung from a tripod and accompanied by a sign indicating how to read it.
Some examples of the instructions for the weather stone include:If the rock is wet, it's raining.
If the rock is swinging, the wind is blowing.
If the rock casts a shadow, the sun is shining.
If the rock does not cast a shadow and is not wet, the sky is cloudy.
If the rock is not visible, it is foggy.
If the rock is white, it is snowing.
If the rock is coated with ice, there is a frost.
If the ice is thick, it's a heavy frost.
If the rock is bouncing, there is an earthquake.
If the rock is under water, there is a flood.
If the rock is warm, it is sunny.
If the rock is missing, there was a tornado.
If the rock is wet and swinging violently, there is a hurricane.
If the rock has white splats on it, watch out for birds.
One example of a weather rock is located at Fort Drum, a US military site in New York state.
There is a prominent and well-known weather rock in the Nature Area of Camp Rotary, a Boy Scout summer camp located in Clare, Michigan.
There is a prominent and well-known weather rock in Camp Wolfeboro, a Boy Scout summer camp located in Arnold, California.
There is a weather rock at the Donner's Pass Historic Site (just outside Lake Tahoe).
There is a weather rock at Bloomington Zoo in Central Illinois.
There is a weather rock in Rhododendron, Oregon near the Zig Zag River off Road 10.
There is a weather rock at the Pancake Bay Trading Post near Pancake Bay Provincial Park, Ontario, Canada.
There is a weather rock in Boron, California, in front of Domingo's Mexican and Seafood Restaurant, a famous astronaut hangout near Edwards Air Force Base.
There is a weather rock at Seven Ranges Boy Scout Reservation in Kensington, Ohio.
There is a weather rock at Firelands Scout Reservation in Wakeman, Ohio.
There is a weather rock outside the McDonald's restaurant in Lithgow, NSW, Australia,
There is a weather rock at Tenterfield in NSW, Australia.
As of late July 2012 Nature Camp in Vesuvius, Virginia also has a weather rock.
There is a weather rock at the Whippi Dip ice cream place at the Pontaluna road in Spring Lake, MI, near Hoffmaster State Park.
There is a weather rock at the Lobster Pot Tea-room on the island of Berneray in the Outer Hebrides, Scotland.
In Australia this joke is similar but with a string rather than a rock. It includes "If the string is on fire then there is a bushfire."