Celebrated on September 23rd
Fall colors are caused by the amount of sugar in leaves. The more red in the leaf, the more sugar that leaf is storing. That is why Maple trees are so vibrant. Evergreens don’t change because their leaves have a thick wax covering that protects the chlorophyl (green) in the leaves. On the date of either equinox (Fall or Spring), the Sun is above the equator and night and day are of approximately equal length; the word equinox is often used to refer to either of these dates.
Monarch butterflies, meanwhile, make autumn a migratory season, flying South from America to the relative warmth of Mexico and parts of California. Traveling at speeds of between 12 and 25 miles per hour (that’s just shy of Usain Bolt’s average 27.8 mph footspeed), they are the only insect that migrates up to 2,500 miles for nicer weather.
Evergreen trees such as pines, cedars, and spruces stay green because their leaves (needles) are covered with thick wax and they contain materials that prevent freezing when it gets cold.