Winter, Spring, Summer and Autumn ... when are they?

[West is Best]

Let me start this by saying that there are clear metereological seasons, but I wondered if people were interested in once again posting what they think the actual seasons are according to prevailing weather patterns. I think my take is as follows:

Winter: 21st December - 15th March

Spring: 15th March - 30th April

Summer: 01st May - 21st September

Autumn: 21st September - 20th December

I think autumn is the one I'm most concerned about at the moment. I've been sure for some time that summer runs on well into September, but we seem to have been losing autumn altogether in recent years - or at least having one that lasts just a few weeks. By the same token winter seems to have got later so hence why I'd run it into March. Spring seems to me to be a short season nowadays, though you could argue that May is a spring month. It half makes me wonder if the ancients had it right in basing it all on the equinoxes ... (which would mean it's nothing to do with GW!)

[Nick H]

Not this one again!

All I'd say is that I think it's stretching it a bit to describe 1 May as the start of summer, even in these warming times. May rarely produces sustained warmth and even the first half of June can be pretty unreliable.

I have just run the average max temp for my location (25 miles northwest of Charing Cross) on 1 May each year since 1979 and it is 15.1C. Since 1989 (often cited as the year the climate took a step change) it is 16.1C. I really don't think you can say those are are typical summer temperatures over a 30 year period.

[androcles]

Let me start this by saying that there are clear metereological seasons, but I wondered if people were interested in once again posting what they think the actual seasons are according to prevailing weather patterns. I think my take is as follows:

Winter: 21st December - 15th March

Spring: 15th March - 30th April

Summer: 01st May - 21st September

Autumn: 21st September - 20th December

I think autumn is the one I'm most concerned about at the moment. I've been sure for some time that summer runs on well into September, but we seem to have been losing autumn altogether in recent years - or at least having one that lasts just a few weeks. By the same token winter seems to have got later so hence why I'd run it into March. Spring seems to me to be a short season nowadays, though you could argue that May is a spring month. It half makes me wonder if the ancients had it right in basing it all on the equinoxes ... (which would mean it's nothing to do with GW!)

I always went by the old fashioned eqinoxes.

ie.

Spring - 21 March

Summer - 21 June

Autumn - 21 September

Winter - 21 December

or thereabouts.

You are right though about the seasons feeling different. I am a gardener and have noticed several changes. For the last eight years or so there has seemed to be less rain in winter/spring. Certainly when I have planted stuff out early March, it has required constant watering. Look at last April. We did not have rain around here for the whole of April and the first week of May. 5 weeks of no noticeable rain. This seems to be a recurring theme now.

There are certainly more pests and diseases around now than used to be. Trees and shrubs get very stressed in these extremes of weather we have had - very dry and hot like last year then sudden flooding or quick cold periods. Whether it's all down to Mother Nature playing its part or AGW I don't know.

It's all very interesting.

Regards

Andy

[West is Best]

Andy that's really interesting. Always great to hear from people working the land who can see what is happening year on year. I must admit I've been heading back to the equinoxes over the past couple of years. They 'feel' more right to me.

Not that I want this to head off into a nature discussion, but our oak trees are looking grim down here (Devon). I thought it was new growth a month or two back, but now there is a white mould on lots of leaves, and many others have died altogether. Do you have any idea what that's about, or whether it's happening elsewhere?

[Thundery wintry showers]

For season 2006/07, I'd say that autumn started on 1st October 2006, and that for some, it's still ongoing! :lol: This August, and also April, were perhaps rather more summerlike for many parts of the country.

Autumn has two main facets for me- the mild wet windy type (which I've mostly associated with the past year), and the crisp type with hazy sunshine by day and often rather cool nights. The second type has been largely missing in recent years although September/October 2003 were pretty good for it.

[KTtom]

Winter: 21st December - 15th March

Spring: 15th March - 30th April

Summer: 01st May - 21st September

Autumn: 21st September - 20th December

I'd almost totally agree with those dates WIB....probably going for winter to start on 1st December though.

KTtom

[West is Best]

I'd almost totally agree with those dates WIB....probably going for winter to start on 1st December though.

KTtom

Yes I'd agree with that too. 1-21st Dec isn't really Autumn. We seem increasingly to go from summer to winter, or at least to have a very short autumn.

[Stratos Ferric]

Let me start this by saying that there are clear metereological seasons, but I wondered if people were interested in once again posting what they think the actual seasons are according to prevailing weather patterns. I think my take is as follows:

Winter: 21st December - 15th March

Spring: 15th March - 30th April

Summer: 01st May - 21st September

Autumn: 21st September - 20th December

...

Playing around with this - and for me the strict definitions stand for reasons of comparability - my wet finger is.

Winter: 16 Jan - 28 Feb

Spring: 1 March - 15 May

Summer: 16 May - 15 September

Autumn: 16 September - 15 Jan

[Nick H]

I've always thought that the astronomical definitions are more realistic than the meteorlogical ones, but I do accept the meteorological definitions for statistical purposes.

I've made an observation further up about spring, but here is my go:

spring: Mar 1 - May 31

summer: Jun 1 - Sep 30

autumn: Oct 1 - Nov 30

winter: Dec 1 - Feb 28

As I expected, some people are going for winter starting either in late December or even in SF's case in mid Jan. But consider that we have had just one mild Decembers since 1988.

[West is Best]

Winter: 16 Jan - 28 Feb

This will not be a popular offer in certain quarters! A six week winter is short even in my book!

I like Nick's suggestions actually I must say.

[Cymru]

Here are mine:

Winter: 21st December - 28th February

Spring: 1st March - 31st May

Summer: 1st June - 21st September

Autumn: 22nd September - 20th December

[Duncan McAlister]

I'm just not sure about September being summer really. A hot summer month should contain spells of uncomfortably hot weather and sultry nights, last September was the hottest on record and still didn't really meet these criteria, not here anyway. It also contained a very autumnal spell around mid-month, although still mild. When we eventually do get a more average September it will feel autumnal (like 2001).

March, meanwhile can be very wintry (occasionally with ice days). This year I recorded a 5C max on the 20th, and 2.8C at midday on the 18th. It can also contain summery maxima around the 21C mark.

Similarly, the beginning of last November felt like winter, the beginning of this May felt like summer and in places the end of it was like winter. Some days this August have had temperatures and weather akin to October.

I don't think you can define what season a month is around its average temperatures. If September is a summer month because the average CET is usually above 14C these days, and a summer month is defined as one with an average temp of 14C+, that means that Scotland technically doesn't have a summer! (Actually, there may be something to the theory :o )

Months can always contain unseasonal weather, so just to be awkward I'd stick with the Met Office definitions!

[Bottesford]

I go with the meteorological definitions of:

June-Aug Summer

Sept-Nov Autumn

Dec-Feb Winter

Mar-May Spring.

I think they work the best for the simple reason of day length. Global warming or not - it's still dark in December and light in June. September is an autumn month as day length almost equal night length (and does exactly on the 21st). If you ignored climate and used day length only summer would be May-July; winter Nov-Jan etc. Take in the thermal lag factor and you arrive at the definitions above. I find the astronomical definitions wrong as it just seems odd calling the day before the longest day of the year 'spring'.

No doubt September can feel like summer (although 25c+ days are still fairly rare) but the days are too short & the Sun too low for it to be actually be summer.

[The PIT]

I go with Bottesford. Although in some years you can almost miss out Winter altogether. :o

[Weather-history]

I define a winter month as a month that can record a sub zero CET and a summer month as a month that can record a CET of 18.0 All other months would be the spring and autumn months.

[Snowyowl9]

Seasonal weather of yesteryear first.

Winter Nov 21st - april 22nd

Spring April 22nd - June 21st

Summer June 21st - August 21st

Autumn August 21st - Nov 20th. :o

As for the average season now.

Winter Dec 1st - March 15th

Spring March 15th - May 15th.

Summer May 15th - September 21st

Autumn September 22nd - Dec 1st.

And this year I`d put it like.

Winter about 20 days(25 days)

Spring in March just and Summer in April and early June and most of august and the first half of september perhaps.

The rest was a very very very long autumn. :lol:

[Nick H]

I define a winter month as a month that can record a sub zero CET and a summer month as a month that can record a CET of 18.0 All other months would be the spring and autumn months.

The trouble with that definition is that, to all intents and purposes, it excludes June. The warmest June was 18.0C a long time ago (I find it dubious, incidentally). What's the next highest after that one? I think 17.3C. June to me is definitely a summer month. Even June 1976 "only" managed 17.0C. And there are only a handful of Junes in the 16s but they would certainly have felt summery.

Whilst I'm at it, your definition of winter precludes any month at all in the calendar year, in this day and age! Furthermore, the last Dec below 0C was in 1890, and there have only been six since 1659.

Take in the thermal lag factor and you arrive at the definitions above

Actually, I think you'll find that the astronomical definitions approximate with thermal lag more closely than the meteorological ones do. For example, I don't have the precise data but I'll wager that the period Sep 1-Sep 20 is warmer than the period Jun 1-Jun 20, certainly in England.

[Roger J Smith]

Winter -- missed it, making a cup of tea (quoting Rollo on that)

Spring -- January 1 to December 31 with brief interruptions

Summer -- Could happen any time but you have to be ready to drive

Autumn -- something they have in America

B)

[shuggee]

In the Scottish 21st Century climate mixing up both experience and potential, for me it's:

Winter 1^st Dec - 20^th March

Spring 21^st March - 20^th June

Summer 21^st June - 31^st Aug

Autumn 1^st Sep - 31^st Nov

Or just recent experience:

Winter 21^st Dec - 28^th Feb

Spring 1^st March - 30^th June

Summer 1^st July - 20^th Aug

Autumn 21^st Aug - 20^th Dec

[I remember Atlantic 252]

winter (or nowadayz extended autumn B) ) 1st Dec - 28 feb

spring 1st march - 31st may

summer 1st june - 31st aug

autumn 1st sep - 30th nov

the way i always say when seasons start

[Weather-history]

The trouble with that definition is that, to all intents and purposes, it excludes June. The warmest June was 18.0C a long time ago (I find it dubious, incidentally). What's the next highest after that one? I think 17.3C. June to me is definitely a summer month.

The warmest June is 1846 with 18.2

[Roger J Smith]

On a more serious note, and if you want seasons of equal length, I feel that the equinox and solstice boundaries start a bit too late and the three calendar months give you something a bit too early, probably the best compromise would be to use a date like the 8th to start the four seasons, meaning

winter 8 December to 7 March

spring 8 March to 7 June

summer 8 June to 7 September

autumn 8 September to 7 December

But if it is more of a question of when these seasons actually prevail, then for the southern part of England at least I would hazard this guess --

winter 15 January to 10 March

spring 11 March to 25 June

summer 26 June to 10 September

autumn 11 September to 14 January

and I would divide the "autumn" into a main autumn season ending 15 December and a transitional season 16 Dec to 14 Jan which is neither true winter nor real autumn, but a snow-free (in general) cold season.

By the way, for comparison, in the Toronto area, that business of 8th of each month works better than either the first or the 21st, and there tends to be a fairly predictable seasonal change around the 7th to 10th of these months. But that's in a part of the world where the seasons are much more distinct.

[Thundery wintry showers]

If June could get close to 18.0C in the 1800s, regardless of uncertainty, it's a practical certainty that given the right synoptics, it could reach 18C nowadays.

I prefer to stick with the meteorological definitions, but if I define "winter" as the period of relatively reliable, potentially lasting snow events, summer as the period when temperatures usually reach at least 17-18C in the North East, and autumn and spring as anything in between, I get the following:

Winter- 16 December to 5 March

Spring- 6 March to 31 May

Summer- 1 June to 15 September

Autumn- 16 September to 15 December

I continued winter into March because of the recent snowy beginnings to March in 2001, 2004, 2005 and 2006 in the North East, and to a lesser extent 2000. There were also some back in the 1990s (1990, 1993, 1995, 1998, and to a lesser extent 1999)

[Nick H]

If June could get close to 18.0C in the 1800s, regardless of uncertainty, it's a practical certainty that given the right synoptics, it could reach 18C nowadays.

It is possible, certainly, but highly unlikely in my opinion: it's the first half of June that is the trouble, the seas are still too cold.

I'm sure the 2nd half of June has measured 18C+ on numerous occasions.

You say "nowadays", but even the Junes of 2003 and 2006 were "only" 16.1 and 15.9C, and they were regarded as stonkers.

On a more agreeing note, your dates of the seasons correlate quite closely to mine.

[Bottesford]

Actually, I think you'll find that the astronomical definitions approximate with thermal lag more closely than the meteorological ones do. For example, I don't have the precise data but I'll wager that the period Sep 1-Sep 20 is warmer than the period Jun 1-Jun 20, certainly in England.

Yes true they do but I take into account day & night lengths into defining the seasons and not just the weather. For me, it's the combination of long days & high temperatures that make summer and short days & low temperatures that make winter. A hot day in late September isn't summer as it's dark at 6pm.