Meteorological Fall began this weekend!
You may have noticed that meteorologists and climatologists define seasons differently from “regular” or astronomical spring, summer, fall, and winter. So, why do meteorological and astronomical seasons begin and end at different times? In short, it’s because the astronomical seasons are based on the position of Earth in relation to the sun, whereas the meteorological seasons are based on the annual temperature cycle.
In order to know where Astonomical Seasons come from, we need to take a look back in history. People have used observable periodic natural phenomena to mark time for thousands of years. The natural rotation of Earth around the sun forms the basis for the astronomical calendar, in which people throughout history have defined seasons with two solstices and two equinoxes. Earth’s tilt and the sun’s alignment over the equator determine both the solstices and equinoxes.
For Meteorological Seasons, Meteorologists and climatologists break the seasons down into groups of three months based on the way the temperature cycles throughout the years as well as our calendar. Most people think of winter as the coldest time of the year and summer as the warmest time of the year, with spring and fall being the seasons the lead to them. That is what the meteorological seasons are based on. Meteorological spring includes March, April, and May; meteorological summer includes June, July, and August; meteorological fall includes September, October, and November; and meteorological winter includes December, January, and February.