After a record breaking warm summer across the U.S., we're finally settling into a comfortable, autumn weather pattern. There are still plenty of temperature fluctuations, which are common this time of year, but no more wicked heat spells that we endured over the summer.
Not only was it a hot summer, but a dry one, too. Much of the center of the country remains in a moderate to extreme drought. If there's one good spin on this, it is that the hot and dry summer may help aid in some spectacular fall foliage across the country.
- US Drought Monitor
The reason leaves change color, in the first place, is because of the colder days and approaching winter. As daylight gets shorter and temperatures start to drop, the leaves recoup nutrients, such as nitrogen and phosphorous. It's the chlorophyll in the leaves that give them their green color through the growing season. Chlorophyll is an essential compound for photosynthesis, which is a process that converts sunlight to carbohydrates.
Leaves are also made up of carotenoids. Carotenoids produce yellow, brown, and orange colors. They are always present in the leaves, but you only start to see them when the chlorophyll process stops. The chlorophyll process stops when temperatures start to drop, which is when the carotenoid colors are revealed.
- Fall Leaves
Wondering where the red and purple hues come from? These colors are the anthocyanins, which are a bit less understood by tree scientists. Some scientists are suggesting, though, that because of the moderate drought there are increased concentrations of these anthocyanins in the leaves, which will lead to some very vibrant hues of reds and purples in the leaves this autumn.
Once the leaves peak, they usually stay on the trees for about five to seven days. Now if there's a really strong storm with very gusty winds, that could blow them off early. Also, remember last October? The Halloween snow? That can put a quick end to peak foliage times.
- October 2011 Snow
I just downloaded a new app to help monitor the changing colors! It's called Leaf Peepr and is a free app that lets you upload pictures of the foliage where you are and where foliage is at its peak. Pretty neat!
- Leaf Peepr
Enjoy all the season has to offer. Get outdoors, take your camera, and capture nature's beauty! Here's what it's like in the D.C. area, as of October 11, 2012
- Fall Foliage In D.C. Area