One of downtown Milwaukee's most iconic buildings and beacons is the Wisconsin Gas Light Building. The Art Deco building was constructed in 1930 as the headquarters of the Milwaukee Gas Light Company, an area utility company that converted coal into natural gas. Atop this unique and beautiful building is a glowing beacon that changes colors - the weather-predicting flame.

The structure is 20 stories tall and features a wide base that tapers as the building stretches toward the sky, culminating in that iconic flame.

That's no accident - the building reflects the shape of a gas flame. WUWM found a pamphlet on the building that says "A pamphlet on the building points out that the architects, Eschweiler and Eschweiler, placed granite bricks at the base of the structure that progressively lightened to cream-colored bricks at the top to "convey a sense of height and majesty."

The unique design of the building creates unique shadows as the sun starts to set and lights come on in the city, making it look even more dramatic.

The building is no longer owned by the utility, but the Art Deco design can be found in all kinds of details and the current ownership group said they're looking to replace or restore other areas of the nearly 100-year-old building.

Though the building itself is plenty beautiful and worth talking about, it's that iconic flame on top that really makes it stand out.

Envisioned as a marketing tool, the light changes color based on the weather forecast, and there is a handy poem to help decipher what the message might be.

WUWM was contacted by the former head of communications for Wisconsin gas who said "The late 1950s and 1960s marked the introduction of natural gas to communities outside the Milwaukee area. The flame, symbolizing a blue natural gas flame, was installed in 1956 to promote the expansion of natural gas for cooking, heating and industrial uses. By changing its colors, it also served as a weather beacon."

There's actually now an iPhone app that you can use for your own weather forecasts that's called "When the flame is blue." It's a nod to this iconic piece of Wisconsin and great nostalgia for those who don't live here anymore.

The pneumonic device Milwaukeeans learned to understand what the flame is telling you is:

When the flame is red, it's warm weather ahead!

When the flame is gold, watch out for cold!

When the flame is blue, there's no change in view!

When there's a flickering flame, expect snow or rain!

During the energy crisis, the flame was turned off to conserve energy. A few years back, the whole flame was reworked so that it does not need to be controlled manually, but works via sensor.

It used to be one employee's job, as part of regular gas level monitoring, to check the weather. That employee would then take care of the flame, which used neon to light up until recently. The lighting was all swapped out so that the flame is now LED. The cost of running the old light was getting prohibitive, but the new, more economical LED lights have helped ensure that this part of the skyline will continue on. Thought it's mostly used for the weather forecast, the light can also be lit up to celebrate local sports teams or holidays - the light possibilities are endless.

The flame is 21 feet tall, weighs four tons, can be seen and used by ships on Lake Michigan as a navigational tool, and can be spotted from incoming airplanes as one of the first recognizable bits of home.

Are you familiar with this iconic part of Wisconsin history? Tell us more in the comments!

Looking for more awesome Wisconsin architecture? Check out this list of some of the most interesting and iconic buildings all across the Dairy State.