There are two types of processes (or reactions): spontaneous and non-spontaneous. Spontaneous changes, also called natural processes, proceed when left to themselves, and in the absence of any attempt to drive them in reverse.
When does fall start in Alabama? Officially, the first day of fall is the Autumnal Equinox on September 23. However, the end of summer is considered to be the day after Labor Day, which is the last summer hâ¦oliday. Autumn leaves in the deep south usually begin in late October to early November. 4 people found this useful.
For example, under the definition of astronomical seasons, the June solstice marks the start of summer in the Northern Hemisphere, but it is the start of winter in the Southern Hemisphere. The same rule applies for the other seasons. The meteorological seasons in the Southern Hemisphere are also opposite to those in the Northern Hemisphere: 1  Fall (autumn) - starts March 1 and ends May 31; 2  Winter - starts June 1 and ends August 31; 3  Spring - starts September 1 and ends November 30; and, 4  Summer - starts December 1 and ends February 28 (February 29 in a Leap Year).