It's no secret that The Grand Canyon State has spectacular sunsets. But, what if we were to tell you that a completely different phenomenon in the sky just occurred? Last week, Arizona's purple sky took residents by storm and you won't believe what actually happened. 

On January 11, early in the morning, the sky glowed purple instead of its usual blue in Snowflake, Arizona. 

The culprit? A nearby medical marijuana farm called Copperstate. Its UV lights were the cause. 

According to Navajo County's Facebook page, "🔎The purple glow is a result of UV lights from nearby medical marijuana farm Copperstate Farms and the snow clouds overhead."

Reportedly, the sky was this unique color for miles around. 

That same morning it has snowed, which is why "Water droplets in the low-lying fog reflected the light, which made it spread across the sky."

Copperstate Farms is the largest greenhouse in North America that grows medicinal marijuana. They use red and blue lights to help produce the plant. 

Since the farm consists of 40 acres, there's no telling if the sky will change colors again. 

Navajo County's post has received over 1,500 shares and 275 comments. Some of the commenters were quick to express how amazing the sight was.

One person wrote, "Beautiful 💜 But I also want to know what caused this?"

While another person said, "The lights are LED lights. The purple glow is a combination of red and blue LEDs. Most plants respond best to these two light spectrums. Pretty isn't it!? I see it every morning driving into work there."

Others found it funny that weed was the culprit of the interesting-colored sky, "The pot farm caused the glow 😂😂😂."

It was a trippy Friday morning, that's for sure. 

Narcity has reached out to Navajo County for a statement and will update this article with any new information.