TAMPA, Fla. (WFLA) – Sept. 23 marks the first day of fall. It officially began at 3:50 a.m. this morning. The correct term for the first day of fall is the Autumnal Equinox.
Today is deemed an equinox because we will experience the same amount of daylight as we do darkness. This is because the sun’s rays are pointing directly at the equator.
The other equinox occurs on the first day of Spring. The earth’s orbit has brought it to the same spot on the side of the sun and the axis also neither points towards or away from the sun.
On the other hand, the first day of winter and summer are given the name solstices. These mark the days with the shortest and longest amount of daylight, respectively. This is due to the earth’s northern axis pointing away from the sun on the winter solstice, meaning the sun’s rays are more directly pointing to the southern hemisphere. Vice versa for the summer solstice.
This is all true for the northern hemisphere, the seasons are switched when referencing the southern hemisphere.