There are two seasonal calendars. Here the first is the astronomical calendar. The second is the meteorological calendar. Read how the two differ.
The meteorological calendar is perhaps the one you are most used to, with Spring starting on the 1st of March, Summer on the 1st of June, Autumn on the 1st of September and Winter on the 1st of December.
The astronomical calendar, with Spring starting on the Spring Equinox, Summer on the Summer Solstice, Autumn on the Vernal Equinox and Winter on the Winter Solstice may need explaining.
So what are Equinoxes and Solstices? As the Earth orbits the Sun the angle at which the sunlight hits the Earth changes and the hours between sunrise and sunset vary throughout the year.
In Summer the days are long. In Winter the days are short. Twice a year the hours of daylight and nighttime are equal as the Sun is directly over the Equator. These are called equinoxes.
There is one equinox in Spring called the Vernal Equinox and falls around the 20th of March. There is another in Autumn called the Fall Equinox around the 22nd of September. These dates vary.
Between the equinoxes are the solstices. The Summer Solstice is when the day is longest and the night is shortest. The Winter Solstice in when the day is shortest and the night longest.
Summer Solstice (June 21st). The Northern Hemisphere is pointing towards the Sun. The Arctic Circle has 24 hours of sunlight. The Tropics around 12 hours. The Antarctic Circle has NONE.
Winter Solstice (December 21st). The Northern Hemisphere is pointing away from the Sun. The Arctic Circle has NO sun. The Tropics around 12 hours. The Antarctic Circle 24 hours of sun.
This picture shows how the two calendars differ. You may have realised that what the Americans call Fall we in the UK call Autumn.
Here the calendars are side by side showing the dates.
So what should you have learned?.....
That there are two seasonal calendars called Meteorological and Astronomical.
That Meteorological calendars are based on months.
That Astronomical calendars are based on the varying lengths of daylight.
That Astronomical calendars are divided by events called equinoxes and solstices.
That equinoxes are when daytime and nighttime are equal in length.
That solstices are when daytime/night time and nighttime/daytime are at their longest or shortest.
That whichever calendar is used the weather is just the same.
That Meteorological calendars are based on months.
That Astronomical calendars are based on the varying lengths of daylight.
That Astronomical calendars are divided by events called equinoxes and solstices.
That equinoxes are when daytime and nighttime are equal in length.
That solstices are when daytime/night time and nighttime/daytime are at their longest or shortest.
That whichever calendar is used the weather is just the same.
Click on each of the sentences to see a picture to help you with your understanding. Click again to hide the picture.