Why leaves change color?

Why leaves change color?
Seasons are changing and so are the leaves. Here is a quick explanation to what causes the change. (Source: KEYC)

MANKATO, Minn. (KEYC) - Today, September 23, is the official start of astronomical fall. That means pumpkin spice flavor is in full swing, winter is right around the corner, and leaves are beginning to change color. So what causes leaves to change color and what weather is perfect for producing brightest most vibrant colors?

Now when it comes to why leaves change color I am no expert. What I do know is that leaves respond to decrease in sunlight from the changing seasons and the change you are seeing has to do with the halting of the chemical chlorophyll. Chlorophyll plays a key roll in the production of food for the tree. Chlorophyll also gives the leaves there green color you see during the spring and summer months.

As days become shorter and cooler weather begins to move in, the production of chlorophyll slows way down. Eventually the production of chlorophyll stops all together. At this point other chemicals begin to shine through producing the vibrant colors you see. Those chemicals and colors associated with them are:

- Xanthophyll (yellow)

- Carotene (orange)

- Anthocyanin (red)

Weather plays a key role in the development of fall colors. For the best and brightest conditions you want a warm, wet spring followed by a summer that is not to hot or dry and a fall with sunny warm days and cool nights.

A warm, wet period during the fall could lower the intensity and/or brightness of the leaves. Also, a early or severe frost could kill the leaves, turning them brown and causing them to drop early.

As of right now, the temperature and precipitation probability outlooks continue to be above average for the fall months. Meaning, leaves will change color but they might not be very vibrant this fall.

Above average temperatures possible through the fall months.
Above average temperatures possible through the fall months. (Source: National Weather Service)
Precipitation looks to be above to near normal over the next 3 months.
Precipitation looks to be above to near normal over the next 3 months. (Source: National Weather Service)

If you capture the fall beauty around you make sure and send your pictures to keyc.com/photos.

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