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Why do leaves change color? The science explained

In Central Florida, leaves usually start changing in November, but warmer-than-usual temperatures have delayed the color change

Fall science

ORLANDO, Fl. – As the days get shorter and the sun lowers in the sky, the intensity of sunlight decreases, signaling to trees that it’s time to prepare for winter. This triggers the leaves to stop producing chlorophyll, the green pigment, and other pigments like carotenoids (which create yellow colors) and anthocyanins (which create red colors) start to show up. Cooler temperatures are key in this process, as they help break down the chlorophyll, allowing the vibrant colors of fall to appear.

Fall science

While daytime temperatures are important, cool nights are especially crucial for producing those bright red colors. The cooler nights help sugars build up in the leaves, which are then used to make anthocyanins, the pigments responsible for red hues.

If fall temperatures stay warmer than usual, like they have so far in November, the leaves may change color later and the colors might not be as bright.

Fall science

During spring and summer, leaves are green because of all the chlorophyll they produce to help the plant make energy from sunlight. But as fall approaches and daylight fades, the tree stops making chlorophyll, and that’s when the reds, oranges, and yellows start to appear.

Fall science

Weather also plays a big part in the color change. For instance, cool nights and extra rain can make the colors more intense and help them last longer. On the other hand, extreme weather like droughts or early frosts can cause leaves to fall off before they have time to fully change.

Fall science

In Florida, trees like the maple, sweetgum, crepe myrtle, blackgum, correl, and cypress all change colors, with the peak fall foliage usually happening in mid to late November.


About the Author
Michelle Morgan headshot

Michelle joined News 6 as a meteorologist in May 2023.

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