Seasons -How are they worked out?

One of the things that’s always puzzled me is when each of the seasons are supposed to start and end. This is typical of someone that over thinks things, really it should be when it’s cold and wet it’s Winter, when the flowers start appearing and the wet is thawing out it’s Spring. Summer is the season of sun, interrupted by heavy rain, with Autumn being the time when one picks blackberries and apples – yup, you guessed it, in the rain!

But when are each of these season’s really supposed to start and finish? I’ve looked at this and there are at least two versions, the meteorological and the astronomical seasons.


Meteorological Seasons

The meteorological seasons are divided up by meteorologists to make weather forecasting easier. The seasons dates are split up as such:

  • Spring – from March 1 to May 31.
  • Summer – from June 1 to August 31.
  • Autumn (Fall) – from September 1 to November 30.
  • Winter – from December 1 to February 28 (February 29 in a leap year).


Astronomical Seasons

The astronomical seasons are a little different.

Spring starts at the March equinox, this is when the length of night and day are almost equal. This happens on either the 19th, 20th or 21st of March. At this point the Sun is directly over the equator.

Summer starts in the June Solstice, this is the longest day in the Northern hemisphere and the shortest day in the southern hemisphere. This normally between June the 20th – the 22nd.


Equinox and solstice illustration.

The September equinox heralds the arrival of Autumn and is the date that again night and day are about equal and this happens on the 22nd, 23rd or 24th of September. This is where the sun is directly over the equator.

This lastly leaves the December solstice, where the shortest day of the year takes place in the Northern hemisphere and the longest day in the southern hemisphere. This takes place between the 20th – 23rd of December.

The seasons are of course opposite between the northern and southern hemispheres as the tilt of the Earth defines the seasons and will be opposite between the north and south.

Simon 🙂

No ownership claimed on image, credit to for information.


67 thoughts on “Seasons -How are they worked out?

  1. Very interesting! And if you want to complicate things further, the old Celtic calendar plots things differently again. It takes the equinoxes and solstices and places them at the middle of the seasons, so spring is February-March-April, summer May-July, autumn August-October, and winter November-January. Many Irish people still divide up their year this way, which confused me no end when I moved to Dublin!

    Liked by 1 person

  2. Your post led me and my oldest on a trip through the web, looking up all things astronomical. I think a telescope is going under the Christmas tree this year. 🙂

    Liked by 1 person

  3. The meteorological seasons seem more logical to me – not that I’m in any way qualified to say so! But that’s when the seasons seem to change… at least here, anyway! Great and interesting post!

    Liked by 1 person

      1. Well we’ve been working hard, I got sick but am on the mend now. Kids are great 🙂 unrelated, but as you know, we homeschool. Our geography club’s country for this month is ENGLAND 😊 I was thinking about discussing words that are different, but can only think of a few: nappy-diaper, wheely bin-trashcan, boot-trunk. Do you have any other word suggestions?


  4. Great post, Simon! Liking the science behind it all. Very informative. Can’t wait for Fall, myself! Thanks, Professor Farnell! 😀😜

    Liked by 1 person

      1. Hmm…talks at the back? I’m not following…do you mean do I sit at the back of the room, or do I talk about the professor behind his back?…

        Liked by 1 person

      2. No way. That is very disrespectful. Even if the lecture is not that interesting, I still am listening and paying attention.

        Liked by 1 person

      3. No way. I think it is very disrespectful if students do that. Even if the lecture is a bit boring, I’m still listening and paying attention.

        Liked by 1 person

It's great to hear from bloggies - feel free to leave a comment :-)

Please log in using one of these methods to post your comment: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.