It happens every fall. The leaves begin to change colors before dropping to the ground to announce the start of winter. But have you ever asked why this happens?

There are a variety of reasons why the leaves on many trees and bushes change from green to a beautiful orange, yellow, or red color before fading away and falling to the ground.

The main reason for the change starts with the lengthening of the night and the shortening of daylight hours that comes with the progression of the fall season.

According to the USDA Forest Service website, chlorophyll gives the leaves their basic green color and is a necessary product for photosynthesis. With the shorter sunlight hours in fall this process slows and will eventually stop.

This allows for the color pigments that are present in the leaves to become visible, thus the change in colors.

Now you may wonder why some years the change in colors seems to come later or earlier in the fall season.  Also that some years the colors seem more vibrant than other years. Part of the reason for that difference can be attributed to the weather pattern and the moisture content in the soil.

KSLA News 12 Meteorologist Ron Young says the weather is crucial to a nice fall foliage display.

Ron Young, Facebook

"To have the most vivid color display it takes warm sunny days, followed by crisp cool nights. The downside this year is we are dry, and the trees need nutrients and water and this drought will probably affect our fall colors."

He noted that some leaves are already turning brown and dropping early.

Young said we are expecting the coolest air of the season so far this coming weekend. It could help the maples and some other trees provide some rich red and yellow colors.

For me, fall is the best season of the year, in part, because of the cooler temperatures and the beautiful transformation of the leaves. Here's hoping we get some rain in time to enrich those colors.