The crisp air and stunning foliage are reasons to love autumn. In Laramie, if you blink you miss those changing leaves. 

According to the US Forest Service, three factors contribute to leaf color metamorphosis: the colors (pigments) in a leaf, the length of night, and the weather. 

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Scientists are still unsure exactly how it works, but they believe it has far less to do with temperature than with actual nighttime duration. Plants need sunlight to grow. The chlorophyll within the plants is what provides the green color. Less sunlight means less chlorophyll in the leaves. 

When the chlorophyll begins to break down due to longer nights and lack of sunlight, some of the other pigments present in the leaf begin to show more prominently. The two second-most common pigments in a plant are carotenoids, which give off orange and yellow vibes (think carrots), and anthocyanin, which colors foods like cranberries and apples to blueberries and plums. Brown is also in the carotenoid family, another fall-esque color. 

Trees in more temperate areas store chlorophyll sugars longer in their leaves. As Laramie goes from summer to winter in about point-three seconds, long, green storage doesn’t happen.

What happens faster is that when the temperature drops as longer nights set in, a tree begins to protect itself by essentially stealing all the nutrients left in the leaf and creating a barrier around its branches. The barrier helps protect it from the harsh cold, but it then effectively seals the leaf off from the branch. Then the drops, unfed and unattached, according to the Smithsonian.

The short of it is: enjoy the sunlight and the colorful leaves because in Wyoming fall, both are brief. 

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