Weather Tidbits: Why Leaves Change Color

This edition of Weather Tidbits will be discussing why the leaves change color in the fall. During the warmer months with longer daylight hours like summer, the tree produces sugars via the process of photosynthesis. This process involves the use of sunlight, water, and carbon dioxide to transfer energy into sugars and energy for the tree. The pigment chlorophyll in the leaves help to absorb the sun’s energy and is what produces the green leaf’s green color. When sunlight dwindles and cooler weather takes hold heading into fall, the tree’s chlorophyll starts to break down. This leaves behind other chemicals that cause the color changes, essentially revealing the leaf’s true color. Yellow leaves feature the pigment xanthophyll, orange leaves feature carotene, and red leaves feature anthocyanin. Bright colors are more likely when late summer is dry and autumn has sunny days and cool nights.