The Sun and the Seasons: Museum Victoria

The Sun and the Seasons

The seasons are governed by the tilt of the Earth’s axis in space as it journeys around the Sun in a year. When the South Pole of the Earth is tilted towards the Sun, this is our Summer. Six months later, when the South Pole is tilted away from the Sun, it's our Winter. In between these we have Autumn and Spring.

Temperatures on our planet are not determined by the distance of the Earth from the Sun. Rather it is the angle of the Sun’s rays striking the Earth. In Summer, the Sun is high in the Sky and the rays hit the Earth at a steep angle. In winter, the Sun is low in the Sky and the rays strike the Earth at a shallow angle.

The seasons don’t begin on one day and finish on another. That's because our orbit around the Sun is continuous. It actually takes quite some time for the Earth to heat up or cool down, and that’s why the seasons change gradually.

So when do we actually start the seasons?

In some parts of the world, such as Australia, seasons begin on the first day of a particular calendar month - in March for Autumn, June for Winter, September for Spring and December for Summer. In other countries such as Britain, it’s accepted that the seasons begin on the dates that the Earth passes four special points in its orbit about the Sun.

Spring Equinox (AEST)

2010 September 23, 1:09pm
2011 September 23, 7:04pm
2012 September 23, 00:49am

The Sun in spring

The Sun in spring
Artist: Frey Micklethwait. Source: Museum Victoria.

On the day of the Spring Equinox, the Earth’s poles are the same distance from the Sun. In Melbourne, the Sun rises due east, sets due west and gets to 52° above the horizon at noon. On this day there are roughly 12 hrs of day and 12 hrs of night.

Summer Solstice (AEDT)

2010 December 22, 10:38am
2011 December 22, 4:30pm
2012 December 21, 10:11pm

The Sun in summer
Artist: Frey Micklethwait. Source: Museum Victoria.

On the day of Summer Solstice, the Earth’s south pole is tilted towards the Sun. The Sun rises south of east, sets south of west and reaches 75 1/2° above the horizon at noon. This is, usually, the longest day of the year.

Autumn Equinox (AEDT)

2010 March 21, 4:32am
2011 March 21, 10:21am
2012 March 20, 4:14pm

The Sun in autumn
Artist: Frey Micklethwait. Source: Museum Victoria

On the day of the Autumn Equinox, the Earth’s poles are the same distance from the Sun. The Sun rises due east, sets due west and reaches 52° above the horizon at noon. There are roughly 12 hrs of day and 12 hrs of night.

Winter Solstice (AEST)

2010 June 21, 9:28pm
2011 June 22, 3:16am
2012 June 21, 9:09am

The Sun in Winter
Artist: Frey Micklethwait. Source: Museum Victoria.

On the day of Winter Solstice, Earth’s south pole is tilted away from the Sun. The Sun rises north of east, sets north of west and reaches 28 1/2° above the horizon at noon. This is, usually, the shortest day of the year.

Comments (111)

sort by: most popular; newest; oldest

thanks, this is super useful information

Exccelent I needed this info for my garden , right going out to my garden right now to plant garlic as your site has made it clear that the Autumn Equinox was on the 20th of march!! so better get those garlics in the ground immidiately, thankyouoooo!, mara

Thanks. Excellent site. One of the few sites that actually understand what a solstice is.

You've peak my interest when you say 'usually' the longest or shortest day. When is the the solstice not the longest or shortest day? Thanks.

thanks a lot, helped me understand what a solstice is

Kristina - information that will answer your query can be found in the March edition of Melbourne Planetarium's Skynotes.

Awesome! one of the few detailed sites about seasons in Australia.. going to bookmark this one. Thanks

great explanation, thanks for making solstices, equinoxes and seasons so easy to understand....

Thank you, brilliant,so easy to understand. I will bookmark this one too.I have my garden prepared now I'll know exactly when to plant.

This site is brilliant, easy to understand, informative. In all of my years learning about our planet, no teacher could EVER explain the Equinox and the Solstice so clearly. Good on everyone who has worked hard to make it such a success. This site is now 'offically' bookmarked! Fantastic work.

When is the shortest day in Victoria Australia thanks Leigh

It was a significant information for me and reply ro my answer. so thank you very much.

Leigh: the shortest day in the year is the Winter Solstice whose dates are mentioned in this info-sheet. Further details about the sun's movements can be found over at this sheet, too.

Thanks for your Equinox explanations . This solved a disagreement I had with a friend about when true spring started.

A Very Excellent page that describes in a easy-to-understand manner. I have searched many other sites for this info and this is "tops".

Thank you for making something so complex, seem so simple. Being aware of the dates now give reason to, the slow start to summer and the long winter!

close this reply

Write your reply to Wizardo's comment All fields are required

Name Please enter your name
Email (will not be published) Please enter an email address
Please enter a valid email
Comment Please enter a comment
How many letters are in the name Victoria? Please answer the anti-spam question Anti-spam question incorrect

We love receiving comments, but can’t always respond.

Hi I have a friend in USA who is a pagan priestess and is coming to australia in December for solstice conference do you have a contact or know of an expert in the solstice field in Australia? thanks for your help

The Discovery Centre can answer questions that relate to Museum Victoria's Collection and Research areas, including Science. If you have specific questions relating to astronomy and meteorology, such as the solstice, you can ask one of our experts on staff by contacting the Discovery Centre directly.

What is the time difference between Melbourne and Wollongong for the Summer Solstice. You note that it is 4.47am is this same time for both locations?

An edited version of our Planetarium staff's response to Stephen's question is as follows:

The Summer Solstice is today the 22^nd Dec at 04:47 Australian Easter Summer Time, or if you look at international sites you will see it listed as being on the 21^st Dec. at Universal Time 17:47.

The actual time difference between Wollongong and Melbourne is immaterial. It is based on the precise time that the angle of the Earth’s tilt is most inclined toward or away from the Sun.

Excellent site. Easy to understand and great diagrams to help explain.

the equinox controls many of the life style habbits of wild animals such as the mating season for wild red deer which is the start of the deer hunting season

So glad to have stumbled upon this excellent site!!!

Excellent Website. I will visit again :-) It answered my questions on Equinox :-)

We had a solar system installed, and I was trying to explain to my husband about how the sun is lower in winter... Thanks for the very helpful website, you explained it beautifully.

Hi, I like to know if there's anyway I can take a compass reading of a building's facing direction using the reference of the sun (to detect a true south direction)? I have problem taking accurate compass reading due to interference of magnetic field from man-made magnetic field (like underground wiring and light pole etc). Hope you can help. Thanks.

Compasses indicate magnetic north or south as they react to the Earth’s magnetic field but that’s offset with respect to our planet’s rotational axis (what most call geographic or true north/south). The direction of magnetic north or south is therefore slightly different. It's possible to find south using the position of the Sun in the sky but it's hard to be really accurate. A reasonable result can be got by observing the motion of the Sun across the sky. Wait for local noon by using a clock on standard time (simpler than having to allow an hour for daylight savings). At that time the Sun will be at its highest point above the horizon, so face the Sun and south will be behind you if you are in the Southern Hemisphere (or north will be behind you if in the Northern Hemisphere). Better still, use a sundial or a tall pole that will throw a shadow towards south at local noon (or towards north if in the Northern Hemisphere). You can then compare compass readings at the building and some well away from it with your noon observing of the Sun. Overall you should get a pretty good facing direction. These websites will give more information:

http://www-istp.gsfc.nasa.gov/stargaze/Snavigat.htm

http://www.wilderness-survival-skills.com/learn-celestial-navigation.html

http://hiker.com/navigation-by-the-stars-and-sun/

Bring on 21 june as I dislike winter and the short days it brings with it

A wonderfully educational site. But let's hurry up and get 21st June out of the way. Bushwalking in Tassie is no fun when it's dark at 4pm!

Thankyou for providing such detailed and informative information!

Great website now I understand more about Solstice and Equinox can't wait for June 21 and longer days.

Great site easy to use and understand

Good site. Easy to understand. Thanks

Great site, good clear explanations and diagrams. Thank you Museum Victoria !

This is rather a stupid and uninformed question but I will ask it anyway - "In plain language without the scientific stuff please, what is the difference between the terms "solstice" and"equinox" - obviously, they don't mean the same thing so what essentially is the main difference.

Excellent description. Why do the times/dates for soltices and equinoxes vary a bit from year to year?

Hi John - The equinoxes occur when the Sun is right across the celestial equator, and so day and night are of the same length for all observers on Earth. The equinoxes happen in March and September. In June and December are the solstices, when the Sun reaches its northernmost (in June), or southernmost (in December) point in the sky, and appears to stop (in its north-south movement) before reversing and heading back in the other direction.

Thank you very much for nice concise information. I came to find the date of the winter solstices but was enlightened by the explanation of the difference between that and the equinox. I probably should have already know that but now I do and it’s thanks to this site

The date and time of the equinoxes and solstices change slightly because the Earth's orbit around the Sun is not precisely 1 year. The equinoxes and solstices happen when the Earth reaches a precise point in its orbit around the Sun.

However the beginning of the year does not happen at the exact same point every year. We count years as being either 365 or 366 days long, but the orbit actually takes about 365.242 days to go from one March equinox to the next.

Thus in a non-leap year, the equinox will be about 0.242 days (approximately 5 hours 50 minutes) later than the previous equinox, while in a leap-year it will be 0.758 days (18 hours 10 minutes) earlier. Note that these figures aren't exact, and the combined effects of gravity from the Moon, the Sun and the other planets also cause a few minutes variation from year to year.

Excellent site, good explanation.Thanks for the information.

So if there was no tilt in the earth's poles, there would be no seasons?

Thank you for saving my marriage and answering when the shortest day of the year is. I knew l was right he knew he was.... and as it happens l was.

Hi Richard,

That's correct - if the Earth's axis was not tilted, we would not experience the seasons as we understand them, since the Sun's rays would not be striking the surface of the Earth at such steep angles. If the Earth was not tilted, the Sun's rays would strike the Earth at a uniform angle.

Yesterday I was reading my original 1829 bound edition of 'The Mirror.' On page 368 was the following assurance: “The tip of the cat’s nose is always cold, except on the day of the (northern) sumer solstice, when it becomes lukewarm.” I’ve put an automated reminder on my computer to check our two moggies’ proboscises at mid-morning next 22 December.

Thanks for the info. I say boo to June 21, we've hardly had a cold day here yet, I've only got to wear my new boots once!! Great site thanks for all the useful information. I will check my cats nose on December 22 as well, although living in mid Qld its likley to be hot anyway near Christmas.

Can you tell me what people who live north of the tropic of capricorn but south of the equator experience. I have been told they experience 2 equinoxes and 2 solstices each time not one. Is this correct or fallacious?

Hi Felicity - It is not true that there are two summer solstices at these locations. The summer solstice happens at a specific point in the Earth’s orbit. What is true is that the Sun will appear directly overhead twice a year in these locations. However this is not on the day of the summer solstice. On this day the day length is longest, and the Sun appears the most southerly, and this will only happen once each year no matter where you are.

Great information thanks. I have one question though, I was told that the equinox also relates to wind, and that typically Victoria is at it's windiest in August & September. can you please advise if this is true, and, if so, why.

very interresting study

Thanks for a brilliant site. Just wanted to echo the previous question; I'd always heard that the equinox effects the wind and that March and September can be much more blowy. Is that true or coincidence? Is there any connection with spring tides too? Thanks

Very interesting and informative website. However, I would be interested to know when Australia altered the change of seasons to the 1st of the month, ie 1st March, 1st June, 1st September and 1st December. As Australian students, in the '50s and '60s, we were always taught that the seasons commenced on the 21st of the aforementioned months in line with Britain.

Hi Ronnie, there is not actually an 'official start date' for seasons. When a season starts on a certain day it is only by convention. There is no government act or universally accepted scientific definition for what constitutes a season.

Most countries popularly use the equinox and solstice dates to 'start' the seasons' but meteorologists around the world start counting the seasons in the same way that Australians do - on March 1st, June 1st etc

Thanks this is very useful seeing as it is the spring equinox.

Thanks - it helped settle an argument with the weatherman!!!

Hi Liz,

We do not believe there is any relation between the equinox, and the weather or tides. However it possibly is more windy between the seasons because that is the pattern in that part of the world at that time, thus, a coincidence.
As far as the effect on the spring tides, it should be pointed out that the “Spring” does not refer to the season in this instance, it refers to an earlier meaning, to spring forward or to rise. This is when the Sun and Moon align to give a higher than normal tide. The opposite of spring tide is neap tide when it is lower than usual.

Thanks, I'm so glad I asked!

thanks its so clear

how long are the solstices?

Hi JB, the Summer and Winter Solstices are a moment in time when the Sun is at its most northern or highest in the sky and most southern or lowest in the sky extremes. This year this will occur on the 21 June at 11:28 UTC time and at 21st December at 23:38 UTC time. So in answer to your question about how long a solstice is, it is just a point in time. Have a look at our infosheet on the path of the sun for more information.

great information thanks. now i know more about the sun and the seasons!

I don't see why we are told here in Australia, that our four seasons start on the first day of the month,i.e. Dec, March, June, Sept. Why is it different to the Northern Hemishphere where the seasons start on the 21st day of these months?

Great site with easy to understand explanations and informative diagrams. Well done Museum Victoria. How refreshing not to have to wade through loads of gobbledegook.

Thanks for the details because this is important to me as I mark the true Saxon Year-teller (calendar) from its erstwhile beginnings, namely, the year begins with the Evennights (Equinox). This year-teller is the perfect one, never needing a leap year and self rights every year at evennights. It dates from the time the law was given to Moses and handed down into Saxon culture because the Saxons get their name from the Persians who called them, the Saka-suni, meaning, Isaac-sons. The Greeks and Romans applied their own versions of this name from whence we get Saxons. The reason the name was given to us was because we we living in bannishment in northern Assyria around 700 BC, becoming lost to history, and were sometimes called the lost tribes of Isaac (Abraham, Isaac, Jacob). Our year-teller has months of 30 days and months were named after agricultural events, such as Winemonth, Havestmonth, Summermonth, Barleymonth and so on. Our weeks of 7 days were called, Onesday, Twosday, Threesday, and so on. Our feest days were the correctional days to fill in the caps to make up the full year.

When watching the moon recently, I have noticed the half moon rising has its bright side facing a southerly direction. I would have expected the light to be coming from the north, seeing its our exquinox. can you settle my mind on this please. I have been thinking its because Earth has had an axis change since the earthquake in Japan. looking forward to hearing from you.

succinct explanation - cuts through the crap that can sometimes accompany astronomical discussion, but then astronomy is never simple is it?

Hi Diana, the bright side of the Moon always faces the Sun of course as that is why it is bright. From Melbourne this would generally mean that the bright side is facing north. The axis of the earth has not appreciably changed because of the recent earthquakes, but may have shortened our day by about a millionth of a second. It certainly would not have changed the sun angle onto the moon.

Thanks for an easy to understand factual site. Very useful for planning my vegetable garden!

thesunrisetimes.com website gives the shortest day in Melbourne in 2011 as being 17th June, whereas the Winter solstice is the 22nd. Why the discrepancy? I am looking to plant onions...

I'm so gald I found this site. I can now succinctly explain the equinox and solstice to my grandkids. They are very interested in the night sky, and your site is easily understandable. Thank you.

Very good information with nice diagrams. It would be better though if you specifically state where on the planet the solstice times relate - Melbourne Victoria I presume?

To try and explain solitice to people visiting the 12 Apostles Visitor Information Centre - Port Campbell is a challenge. Thankyou this has made it much easier

Thanks for such a succint explanation for what can be a confusing topic. We always like to know when the shortest day is as, knowing that each day from then will be slightly longer, lifts our spirits. This is especially relevant for people who suffer from Seasonal Affective Disorder (SAD).

Thank you Museum Victoria. I am giving a talk about the winter solstice tomorrow night and it was difficult to find books to answer my questions. Now I know exactly when the farthest axial tilt occurs. I didn't realise it was different every year. I was interested to read about the similarities of the celebration in so many cultures.

We didn't realise the winter solistice occurred on different dates each year. We were thinking it was happening today.

i have increasingly become more interested in the correlation of the planetary alignments and seasonal changes and this site has so much easy to understand explainations. i am so greatful for your input and comments. A City Farm not far from where i live celebrates the winter solstice every year with the community and interested ones who come along to join with us... so thank you for the accurate info.. Alan

Great web page. I've been counting down to 3.16am June22. For future reference what latitude and longitude are your times for? I'm in Toorak and I was wondering how I could calculate the solstice and other things for my location. I'm a curious sort.

Hooray it's Winter Solstice Today :D

Thanks - what I don't understand is how these solstice's (solsticii?) can be seen as marking the beginning of a season...? I would think they actually mark the mid-point of the season. E.g surely the summer solstice (when the sun reaches its zenith...) should really be mid summers day shouldn't it...?

thanks alot, now I have lost a bet with richie saying that the winter solstice was yesterday. gosh

You might want to note that in the Northern Hemisphere these are naturally the opposite, i.e. The Southern Hemisphere Winter Solstice is Northern Hemisphere Summer Solstice etc..

Thanks for the excellent, uncomplicated and easy to understand explanation!!!!

I think I just lost a bet with my daughter(12). Great information and very easy to understand. I also like that you answer people's questions and obviously know what you are talking about and that you are an Aussie site with relevant information to us Aussies. Thank you

Hi Mary, all our times and charts are for Melbourne at 37° 49’ 00 S and 144° 58’ 00 E. The times are local times adjusted for daylight savings. Now, as far as solstice and equinoxes go, they are all at the same Universal Time or GMT, and are given in local times.

The following web address should assist with any other queries you may have: http://www.ga.gov.au/geodesy/astro/moonrise.jsp another good site is : http://aa.usno.navy.mil/

Hi Alan, when seasons officially start and stop is a local convention that countries and communities adopt, and it depends on your latitude as well. If you are in the tropics then there are only two seasons: the wet and the dry. Our aboriginals have 3 to four seasons again depending on your latitude. See this great web site: http://www.bom.gov.au/iwk/climate_culture/Indig_seasons.shtml

The Summer Solstice in Melbourne is generally not the hottest time of the year as the earth hasn’t heated up fully, and is usually mid to end January. So you could say this is mid- summer in Melbourne. Season times as can be seen are purely local convention and are based about the solstice.

Wow! This is top quality information! Thanks for the information and keep up the good work!

Absolutely brillian information and explanation. Am well equipped to teach about seasons to my students.

Excellent, concise and easy to understand. Makes sense of the seasons and how they are gradual things, not totally distinct like we often imagine.

Excellent, we are in process of building the house and this information helps us lot in deciding the pergola roof and the garden beds

more need to said regarding the so called Australian - season starts. The simplilton accepted notion that the first day of a calender month like say Spring being Sept 1 or Summer as Dec 1 etc has as it's 'dubiuos' roots the need to push the period ahead of it's natural time is entrenched in institutions like retailers who want to announce the next sale ahead of competitors. Or moronic radio annoucers beating up something from nothing. Lets talk about that please so we can educate our people to the hijinx and robbery of a natural culture of which we as human being are more in tune with. Come on - get rid of it.

Thanks once again for your most informative expose on the equinoxes. Because of you I (Thomas) won a bet with my twin brother about the date of the autumnal equinox (southern hemisphere) - Matt thought it would be 21st March but I bet on the 20th march - so thanks for verifying my prediction and winning me some money.!!

Hi Pauline, this link should give you the answers you are looking for.

i havant found what im looking for

Hi Abby,
We're sorry to hear that. You can submit any further questions you have through our 'Ask the Experts' website.

Just the information I was looking for and pulled it up with the first go on a google search. Thanks!

I am an old man and once read that the British used March 1st as the Date that they put their servicemen here into Winter Uniforms and September 1st into Summer Uniforms. It is interesting to note that the Mother Country does not use the same dates. I agree with others that Australia should use the dates about three weeks later that most countries use.

Just the information I was looking for and so easy to find. I love the art work. So why does Australia use the 1st of March as the start of Autumn?

Hi Jenny, Good question! See our answer to Ronnie's question (above - 17 September 2010).

mad

I thought the Equinox was on the 20th March and 22nd Sepember

Hi Don, the Planetarium staff have said that the dates on this link are correct. The Spring Equinox occurs at 00:49am on the 23^rd Sept. 2012 but on the other side of the Earth it occurs on the 22^nd September.

Happy Winter Solstice! Looking forward to longer daylight!

my class 7d leap grade is learning about the winter solstice today

My class is laerning about this in class. :) :)

Very helpful information. Thanks! :)

Useful info.

When seeing Earth diagram seasonal tilt models most people show Earth tilted toaward Left. Sometimes this is confusing because some use tilt to the Right and again makes one confused on the 4-seasons like on Anartica vs. the Artic.

I don't see any mention of "Aprillion/ Parillion. 4th January/4 July". When the Southern Hemisphere is closest to the Sun. And Northern Hemisphere furtherest away.

I really like this information but could it be updated for 2013 and 2014 please.

the first drawing is wrong. The seasons should be labeled in one hemisphere only. On the right part of the first drawing, the northern hemisphere receives more thermal energy from the sun. So the label should be summer in the northern hemisphere.

Hi wisegeek - we passed your comment by our Senior Curator of Astronomy, and the response was that the drawing you refer to is not wrong, it is correct and corresponds to the seasons in the southern hemisphere. The left most Earth is summer in the southern hemisphere and the right most Earth is winter in the southern hemisphere.

Hi. Is there an up dated page for "The Sun and the Seasons"? It only shows equinox and solstice dates to 2012. Like your site. Dave

The Sun and the Seasons

So when do we actually start the seasons?

Spring Equinox (AEST)

Summer Solstice (AEDT)

Autumn Equinox (AEDT)

Winter Solstice (AEST)

Comments (111)

Recent Comments

Tweet

Join Up & Join In!

MV Links

MV Membership

MV E-News