KDKA-TV Weather Beacon atop the Gulf Tower

From its construction in 1932 to the late 1970s, the Gulf Tower Building in downtown Pittsburgh, Pennsylvania, USA, was more than just an iconic part of the city skyline — it also served as a rudimentary weather forecast system for pedestrians on the city streets below. Red and blue neon tube arrays mounted on the step-pyramid peak of the 44-story edifice provided the city with a simple, color-coded forecast system: red light signified fair weather ahead, while blue light meant rain or snow. If the light was steady, the temperature was predicted to rise; if flashing, to fall.