A weather beacon is a device that shows the local weather forecast using a system of colored or flashing lights. A short poem or jingle is often used with the code to help people remember it.

The beacon is usually located on the roof of a tall building in a downtown area, but some are attached to towers. Most beacons are owned by financial services companies and television stations as part of their advertising and public relations efforts. They give a basic forecast for the general public, not to help with navigation.

In addition to showing weather forecasts, some beacons have been used to signal victory or defeat for a professional sports team's home games.

History

In 1898, U.S. President William McKinley ordered the installation of coastal warning display towers along the coast of the United States. In 1936, the Weather Girl sculptures were placed in City Hall Square in Copenhagen. In 1938, Douglas Leigh designed a Coca-Cola billboard with a weather forecast display at Columbus Circle in New York City.

The first attempt to use a weather beacon for advertising was by Douglas Leigh, who, in 1941, created a lighting plan for the Empire State Building to show a weather forecast code. A decoder was to be included with Coca-Cola bottles. The plan was not used because of the attack on Pearl Harbor later that year. Leigh revived his idea in October 1949 in Minneapolis with the Northwestern National Bank Weatherball.

In Australia, MLC placed weather beacons on its buildings in North Sydney and Melbourne in 1957 and 1958. Weather beacons were most popular during the 1950s and 1960s.