Why do leaves change color? Actually, the leaves are really always the color that you see during the fall, but the chlorophyll in the leaves is green. Chlorophyll is important in the process of the trees taking water and sunlight and making it into nourishment. When the days shorten and the sun gets lower in the sky, the chlorophyll is not replenished in the leaves.When the chlorophyll breaks down, you get the bright colors of autumn. While cold is not as important to start the process, colder weather speeds along the breakdown and can help bring out those colors more.
Because the sun angle is lower to the north in the first place, the lowering sun effects the northern areas first. The upper Midwest and New England are the first to see the colors. Large lakes moderate temperatures and therefore slows the process around the Great Lakes for a little.
Here is the latest Fall Foliage video update.
Here are the average Peak color times.
Here are the current color conditions.
