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

[Terminal Moraine]

Apart from the usual meteorological definitions of the different seasons in an 'average' year here I'd go for the following.

Winter Nov' 15th to March 20th

Spring March 21st to June 10th

Summer June 11th to August 31st

Autumn September 1st to November 14th

T.M

[mushymanrob]

tbh i too think that in general summer stretches into september, dispite the rapidly shortening days and lowering sun. but, thats about to only adjustment id make to the 'met' version of summer. to me june 1st-20th isnt spring, the suns high, days are very long and the weather is summer. likewise the first three weeks of march and december are imho spring and winter respectively.

[Anti-Mild]

Winter: 16 Jan - 28 Feb

Now I may be wrong and if I am then I will hold up my hand and apologise but that seems to be deliberately inflammatory !

Had I been asked this question 5 years ago I would have had a definitive answer and it would have been something like this:

Spring: 15th March - 31st May (78 days)

Summer: 1st June - 31st August (92 days)

Autumn: 1st September - 30th November (91 days)

Winter: 1st December - 14th March (104 days)

Now, taking into account climate variability, recent trends and flowering seasons I would amend this to:

Spring: 8th March - 20th May (74 days)

Summer: 21st May - 7th September (110 days)

Autumn: 8th September - 30th November (84 days)

Winter: 1st December - 7th March (97 days)

So summer has, from my perspective, lengthened by more than 2 weeks with all other seasons suffering as a result.

[Summer of 95]

I perceive the seasons thus (average dates; they can vary but seldom more than 10 days either side):

Season A: About Dec 10-Feb 20: When Ice Days and lasting snowcover are possible and temps over 10C should be rare (though less so in recent years)

Season B: Feb 21-April 10: Snow is just as likely as in season A but seldom sticks on the ground for more than 1 day, very low minima are also common but subzero maxima very rare. 15C expected at least once towards the end of this season.

Season C: April 11-June 10: Should be a dry time of year; daytime temps increase from mild (~15C) to warm (~21C) as the season progresses, though nights can still be cold and occasionally frosty. First clap of thunder heard towards season's end.

Season D: June 11- July 15: A very variable season that can be either a scorcher or a washout at any given time. Most days should reach 20C but there can still be the odd sub-15C max.

Season E: July 16-Aug 21: High summer. Maxima below 15C almost unheard of in the CET zone and roundabout; 20C can reasonably be expected over most of England on any given day. Rainfall varies greatly from year to year but sunless days should be few and far between.

Season F: Aug 22-Oct 10: Another variable season, in some years scarcely cooler than season E but in others depressingly dull, wet and windy. Cool nights reappear but most days still above 15C.

Season G: Traditionally Oct 11-Dec 10; cold, frosty, foggy nights and crisp bright days; frost becoming more frequent and daytime temps lowering from ~15C to ~5C as the season progresses. Perhaps a snowflake or two towards the end. This season however seems to have largely vanished in the last 10 years; being replaced by a guaranteed monsoon throughout October and a November that suddenly jumps from season F to A in a couple of days.

[Stratos Ferric]

...Season G: Traditionally Oct 11-Dec 10; cold, frosty, foggy nights and crisp bright days; frost becoming more frequent and daytime temps lowering from ~15C to ~5C as the season progresses. Perhaps a snowflake or two towards the end. This season however seems to have largely vanished in the last 10 years; being replaced by a guaranteed monsoon throughout October and a November that suddenly jumps from season F to A in a couple of days.

That's one tradition that seems to have passed by these northern outposts. Is Shrewsbury far from Telford (you don't need to answer)?

[Stratos Ferric]

Now I may be wrong and if I am then I will hold up my hand and apologise but that seems to be deliberately inflammatory !

Had I been asked this question 5 years ago I would have had a definitive answer and it would have been something like this:

Spring: 15th March - 31st May (78 days)

Summer: 1st June - 31st August (92 days)

Autumn: 1st September - 30th November (91 days)

Winter: 1st December - 14th March (104 days)

Now, taking into account climate variability, recent trends and flowering seasons I would amend this to:

Spring: 8th March - 20th May (74 days)

Summer: 21st May - 7th September (110 days)

Autumn: 8th September - 30th November (84 days)

Winter: 1st December - 7th March (97 days)

So summer has, from my perspective, lengthened by more than 2 weeks with all other seasons suffering as a result.

Not at all. I think that at pretty much any time in my life you'd struggle to define and substantiate (as you have) a winter that's longer than summer, and certainly as recently as the 1990s.

If realistic prospect for snow and frost (as opposed to occasional outliers), coupled with low daytime maxima, is taken to define winter then December is increasingly disappointing. The last 3-4 Decembers have certainly reached mid-month before any prospect of genuine winter cold was seen. I was perhaps a tad harsh suggesting mid January, but certainly pre-Christmas wintriness is becoming a scarce commodity; when I was a kid growing up decent pre-Christmas snowfall was a much better than evens bet.

Recent winters HAVE delivered, to some extent, in early March, but this seems to be at the expense of early season cold: hence, my margins are something of a compromise between oscillating extremes.

The other problem with this "game" is that the seasons do not abut neatly and consistently. I well remember in 1981 or 1982 playing tennis mid April in the low 20s ©, and then wading through 15" of snow a couple of days later. Equally, snow fell - and settled - hereabouts in October 1992 and 1993, but the winters that folowed delivered little (thogh late Nov and early Dec 1993 were both fairly snowy for the time of year).

[damianslaw]

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)

I said yesterday in a thread that i generally use the equniox/solstice dates as the boundary between each new season, however after further thinking I very much agree with your definition, especially as I also live in the north east.

Definately the first two weeks of March belong to winter, in recent years this period has been more often than not marked by winter conditions. Although early June can feel spring like still rather than summer, it is just too light and the sun too strong to put it into the spring category, so okay i agree that June should be classed as summer, though I never expect summery conditions to really develop until middle of the month. September yes spot on the first two weeks often bring very settled dry and pleasant conditions ( a la this year ...) not something you associate with autumn, also if we have had a hot august the heat tends to stick around during the first two weeks of september.

Autumn yes i would definately stretch into the first two weeks of december, although it is nearly the darkest period of the year, it is often associated with unsettled mild south westerly airstreams rather than cold wintry weather, though there is often a very sudden change mid month.

[SnowBear]

Think I would go along with Bottesford as well.

June-Aug Summer

Sept-Nov Autumn

Dec-Feb Winter

Mar-May Spring.