With autumn comes cooler temperatures and shorter days. The September Equinox, also known as the Autumn Equinox, marks the end of the summer and the start of the autumn in the Northern Hemisphere. Read on to find out when the Autumn Equinox will occur this year.
The first day of autumn depends on what season you use.
There are two separate dates which could be said to mark the start of the Autumn season.
The date autumn begins depends on whether you use the meteorological season or the astronomical season.
READ MORE: When is the Autumn Equinox? What is the meaning behind it?
When is the first day of autumn in the meteorological season?
Put simply, the meteorological season splits the year into four seasons of three months.
The meteorological season is based on the Gregorian calendar.
Every year, autumn lasts from 1 September until 30 November.
Under this system, spring occurs between March and May, and summer starts in June and finishes in August.
When is the first day of autumn in the astronomical season?
In the astronomical season, the date autumn begins can change yearly.
The day the autumn begins is marked by the position of the autumnal equinox.
At some point, the Sun will pass directly over the Earth’s equator and daytime will last as long as the nighttime.
This day is known as the Autumnal Equinox.
When is the September Autumn Equinox this year?
This year, the autumnal equinox is on Monday, September 23, 2019.
Winter begins on the date of the winter solstice under the astronomical season, which will occur on Sunday, December 22, 2019.