With another wet weekend ahead, the familiar grumbles about British summers have surfaced. Are we deluding ourselves that they should be any different, asks meteorologist Philip Eden.
The British summer, it has been said, consists of two fine days and a thunderstorm.
This assertion has been variously attributed to Charles II and George II, although Richard Inwards' volume, Weather Lore, perhaps wisely regards its originator as anonymous. George II would, I suppose, be the more likely of the two monarchs to have uttered the line - he did after all grow up in Germany where summers are generally warmer and sunnier than they are in the UK.
Most of the summers we experience in Britain... usually contain one or two of those mini-heatwaves followed by thunderstorms
Whatever its genesis, this old saying is rather nearer the mark than the more romantic image of high summer weather in Britain - long, hot, hazy days in the sun, crowded beaches, parched gardens, uninterrupted cricket on the village green, and so on.
July and August, on average the warmest months of the year in most parts of the UK, do from time to time comprise a succession of days of Mediterranean-blue skies, blazing sunshine, and soaring temperatures, but these months are rare enough to become imprinted on the community memory - 1911, 1933, 1959, 1976, and 1995, for instance.
The legendary 1976 summer stands out and generally temperatures have risen
Just as infrequently, these high summer months contain no settled spell at all and only one or two isolated days when the warmth of the sun allows us to shed the ubiquitous mackintosh. This happened last year, of course, but we have to go back to 1988 to find another example.
Most of the summers we experience in Britain lurk somewhere between these two extremes: they usually contain one or two of those mini-heatwaves followed by thunderstorms, but with plenty of indifferent weather in between.
Some people say that the 2008 summer has been the worst in living memory but that only shows that people's perceptions are the worst thing to use when categorising a summer, because memories are fallible and summers are always described as the worst or the best when the truth lies in between.
Hugely variable rainfall year to year, and the drought in 1976 stands out
This summer has been a classic, old-fashioned British summer, even supporting the theories of Professor Hubert Lamb, one of Britain's best-known climate experts, who analysed weather patterns over a period of about 100 years to determine whether any of these patterns tended to recur at particular times of the year.
While acknowledging that our weather varies enormously from year to year, Lamb did succeed in determining certain recurrent themes which he called "singularities", although he emphasised they were not reliable or regular enough to be used as a forecasting tool.
The very notion of cramming Wimbledon, Ascot, Henley, the Lord's Test match, hundreds of church fetes, and thousands of back-garden barbecues into the second half of June is clearly an act of extreme provocation
Two of Professor Lamb's summer weather patterns have been firmly in evidence this year. He dubbed the period mid to late-June the "return of the westerlies" and mid to late-July "thundery and cyclonic".
After several months when winds from a westerly quarter are conspicuous by their absence between mid-February to early-June, they return with a vengeance around the middle of the month. Picking up moisture across the Atlantic, that means wet weather that lasts about a month.
A few statistics will help to illustrate the point. During the last week of May, westerly winds are dominant in only 15% of years, but by 20 June that figure has increased to 52%. During July, the frequency of westerly winds declines slightly to about 40% while cyclonic weather types increase, reaching a peak of 35% by the end of the month.
Lamb's "return of the westerlies" is these days more usually called the "European Monsoon". This is the original use of the word "monsoon" which derives from the Arabic word for "season", and refers to the seasonal wind regime in the tropics - especially in the Indian subcontinent - rather than the more recent and erroneous "heavy downpour" meaning of the word.
For the layman, the European Monsoon is simply the way that it always seems to rain when Wimbledon arrives. The very notion of cramming Wimbledon, Ascot, Henley, the Lord's Test match, hundreds of church fetes, and thousands of back-garden barbecues into the second half of June is clearly an act of extreme provocation. Is it any wonder that Mother Nature cannot resist?
Wet Wimbledons might not be merely unlucky
The effects of these returning westerly winds are felt most strongly in northern and western Britain, and in particular the highlands and islands of Scotland. In these parts of the UK, July rainfall is double what it is in May, while sunshine duration declines sharply: on the Isle of Skye, for instance, the sun shines for an average of 203 hours during May, 174 hours during June, and just 122 hours during July.
Professor Lamb's westerly winds run into the "thundery and cyclonic" period during mid to late-July That means the temperature rises a little bit and it feels warmer at night but the rain continues.
This weather pattern, that usually lasts into the third week of August, ties in nicely with the ancient St Swithin legend which promises us 40 days of wet weather should it rain on St Swithin's feast day, 15 July 15. Conversely, a fine St Swithin's Day should deliver 40 more days without rain.
Every year the newspapers take great delight in proving St Swithin wrong, and reputable scientists have wasted many pages in journals proving that the saying has never come true. These scoffers and mockers all miss the point.
Our ancestors were keen observers of the weather, and they evidently picked up on the marked tendency for the weather to become locked into a particular pattern for five or six weeks from the middle of July onwards, long before Lamb and his contemporaries had the scientific wherewithal to explain why.
Rather than scoff, we should doff our caps to them.
Philip Eden is author of Great British Weather Disasters
Below is a selection of your comments.
Philip Eden is absolutely right! The truth is that in the last two decades British people have come to regard fine summer weather as their due (encouraged by the summers of relentless heat such as 89,90,94,95,97,03,06) and therefore catastrophise summers like this one (which is entirely as an English summer should be). I grew up in the 70s and yes 76 was memorable but 77 and 78 were both hideously cold and wet for the majority of the country (slot last year's "dire" summer into the 1960s - a very cold decade - and it would come out at third warmest).
Gerard Mackay, Hove
The only people who can possibly think 2008 is the worst summer in living memory would be babies under the age of one as 2007 was hardly a classic! This feels like a perfectly normal summer to me...
David Worton, Southend On Sea
I love the British summer not too hot and not too cold. It is unpredictable, you never know to take a brolly or a sun hat or both.
You have to realise that England's green and pleasant lands would be brown and arid if not for all our weather where would you enjoy the green rolling hillsides then....
Trevellyon Newell, Chilton, oxon
This is a very informative article and should be read carefully, both by global-warming deniers and by people who complain without reason about wet weather in June or July. I have noticed the cool wet spell of westerly winds in June over many years but my friends usually scoff at the idea, so I am glad to see it confirmed by historical analysis. The rainfall graph also confirms my purely personal recollection that 1987 was the wettest summer that I can remember.
Graham Gould, London E10
What seems different over the past couple of years is the very cold background wind. It would be interesting to know what the wind chill factor is today because out of the sun it is cold.
Richard Wood, Ripley, Derbyshire
I guess I fall into the category of having "an imprinted community memory"... I have no axe to grind with statisticians or reason to believe their data is inaccurate, but the figures just don't seem to add up with my childhood memories. I was born in 1975 and if I look back at our family albums from around 1980 to, say 1987, the one thing that stands out is brown lawns. I'm sure parched, rock-hard lawn was a regular feature from my youth, yet I can't recall seeing a dead lawn in the West Country for the last decade. I can believe I'm liable to give fond memories of particularly hot days more credence in my mind, but surely the dead vegetation is evidence of prolonged hot periods and lack of rain isn't it? Not to mention the fact that there used to be at least one good sledging/snowballing day each Winter... Yours in collective delusion.
Andy Platt, Bath, United Kingdom
Utter drivel - the worst kind of blinkered, head-in-textbook statistician nonsense! This is unquestionably the worst summer in memory in this part of the country. We have had no more than three consecutive warm, T-shirt-only days, and the winds have been so bad that our roofer has been unable to fix the damage caused in the "spring" (don't make me laugh) gales, due to bad weather backlogs. I actually resent whatever portion of my licence fee was used to solicit or research this piece, and every penny spent on so-called weather "forecasting" - and I'm a strong supporter of the licence fee!
Quentin, Brighton, UK
Does this mean that we can now fairly laugh in the face of all the climate change lobby who are claiming our current weather proves that climate change is real and is happening NOW?
Brian Hill, Oxford, England
The quality of the British Summer is a combination of weather, attitude and clothing: you just have to have a decent hat and coat (or a love of splashing in puddles while soaking wet, something we should avoid growing out of) and the intelligence to see that 15 minutes of rain spread over eight hours is not the same as "it rained all day"
Jason, Herts, UK
Late June - you forgot to mention two other rain magnets: the Glastonbury festival, and the British Grand Prix at Silverstone...
Andy, Brighton UK
So over a period of 50 years, weather has basically done the same thing, and is cyclic. Does this throw global warming alarmist theories out the window?
Paul Harrison, cambridge
I always remember May into the start of June being lovely after years of school exams, GCSEs and A Levels, then university exams meaning I spent my time indoors during the nice weather. The summers have been more mixed, I remember our camping holidays being complete washouts a couple of times in the 1990s, but some lovely years too. It does seem May is the most predictable month though, two of my friends' birthday is May 12, and both say they rarely remember a birthday they didn't enjoy the sun and heat enough to wear shorts and T-shirts!
Phil Eden's comments focus on winds only insofar as they affect rain and sunshine, but what many of us have noticed is that wind strengths are much greater and have become a limiting factor for many outdoor activities. Look at the top picture in the article
Iain MacKenzie, Bath