Weather of Arabia - We usually feel the beginning of autumn when the nights begin to lengthen, temperatures become cooler, and the colors of tree leaves change, but is there a fixed date for the beginning of autumn? And when does the fall semester start this year 2022?
In fact, there are two separate dates that can be said to represent the beginning of autumn, one of which is based on the astronomical start of autumn, and the second is a fixed date that meteorologists use to determine the beginnings of the seasons, but it is not the official start.
The beginning of the autumn season is astronomically the official beginning of it, and the astronomical beginning of the seasons determines the tilt of the Earth’s axis as it revolves around the sun, which leads to the two halves of the Earth receiving a different amount of solar radiation, so that either half of the Earth tilts towards the sun and the season is summer or it tends away from the sun And the season is winter.
As for the beginning of the autumn season, it is the day of the autumnal equinox, and the date of the autumnal equinox in the northern hemisphere comes in the month of September, and in the southern hemisphere it comes in the month of June, and the autumn season extends until the day of the winter solstice.
The day of the autumnal equinox with which autumn began last year was on Wednesday, September 22, 2021, and ended on the day of the winter solstice (Tuesday, December 21, 2021).
As for this year, the fall semester begins on Friday (September 23, 2022) and ends on Wednesday (December 21, 2022), so that it lasts 89 days.
You may also be interested in: What is the autumnal equinox and why is it so important?
Meteorological seasons are derived by dividing the year into four periods, each spanning three months. These seasons are divided to coincide with the beginning of the months, which facilitates the process of monitoring and forecasting and comparing seasonal and monthly statistics.
According to the meteorological calendar, the first day of autumn is always September 1, and ends on November 30 , meaning that the autumn semester in meteorology extends for 3 months: September, October, November.
The astronomical entry of the northern part of the globe in the autumn does not necessarily mean direct changes to the weather, such as a drop in temperatures or instability of the weather. Especially those located on the Mediterranean basin.