But in the fall, because of changes in the length of daylight and changes in temperature, the leaves stop their food-making process. The chlorophyll breaks down, the green color disappears, and the yellow to orange colors become visible and give the leaves part of their fall splendor. Temperature, light, and water supply have an influence on the degree and the duration of fall color.Early frost will weaken brilliant red colors. Rainy or overcast days tend to increase the intensity of fall colors.
So enjoy them while you can! And send some my way...I really miss the show this time of year.
Info and images found here