The weather rock or weather stone is a humorous 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.

[1] A portable example of such a display, "the famous Maine Weather Stone" of Audubon Camp, Hog Island, was described in late 1981.

[2] Some examples of the instructions commonly provided for "reading" a weather rock include: Weather rocks will sometimes include rules for proper maintenance of the system such as, "Please do not disturb the weather rock, it is a finely tuned instrument!"

In certain circumstances the string may be incorporated into the saying: Weather rocks are located all over the world.