Here comes the sun. Perhaps.

I hope you’ve been enjoying the summer sun because according to the Anglo-Saxons it’s nearly autumn.

A thousand years ago summer officially started in England on May 9 according to an Old English calendar poem about the year called the Menologium. This was a kind of early almanac dating from the late 10^th century which confidently asserted that from this date on it will be sunny and warm, meadows will flourish, and everybody will feel good about life. An 11th-century calendar held in the British Library concurs, explicitly noting that on May 9 “Here begins the summery heat for 7 multiplied by 13 [days]” with a note in the margin stressing that the day is ‘The beginning of summer’ and that autumn will commence on August 7.

Not that autumn necessarily nixes the sun. The term ‘Queen’s weather’ was a much-used phrase referencing the belief that whenever Queen Victoria appeared in public it turned out nice again. Charles Dickens mentions it in his magazine Household Words in 1851: “The sky was cloudless; a brilliant sun gave to it that cheering character which – from the good fortune Her Majesty experiences whenever she travels, or appears publicly – has passed into a proverb, as ‘The Queen’s Weather’.

Wherever you place the starting point for the summer, one seasonal experience that hasn’t changed over the centuries is the traditional British heatwave. Here’s a January 1606-07 entry in a local parish register for Arlingham, Gloucestershire:

a great flood with a strong south-west wind, many sheep and cattle lost. The somer following there was a most extreme hot somer, in so much that many died, with heat.

A little later that century the famous diariest Samuel Pepys also felt the sizzle. His note for June 7, 1665, reads:

It being the hottest day that ever I felt in my life, and it is confessed so by all other people the hottest they ever knew in England in the beginning of June, we to the New Exchange, and there drunk whey, with much entreaty getting it for our money, and [they] would not be entreated to let us have one glasse more… So by water home, where, weary with walking and with the mighty heat of the weather, and for my wife’s not coming home, I staying walking in the garden till twelve at night, when it begun to lighten exceedingly, through the greatness of the heat.

Nearly 200 years later, notable Scottish letter writer and wife of historian Thomas Carlyle, Jane Carlyle wrote this to her friend Mary Russell, on June 27, 1858

 “It is so long since I wrote… I can only say I have had plenty of excuse for all my sins of omission of late weeks. First, my dear, the heat has really been nearer killing me than the cold. London heat! Nobody knows what that is till having tried it; so breathless, and sickening, and oppressive, as no other heat I have ever experienced is!”

Of course the sun hasn’t always shone when it was supposed to. 1816 was probably the worst summer ever for sunbathers in Britain and has become known as the Year Without a Summer. Bizarrely cold temperatures were caused by the previous year’s eruption of Mount Tambora in modern day Indonesia which caused a volcanic winter. British data shows it was the coldest July ever recorded.

So the important thing is to make the most of it when it’s here. George Harrison started writing ‘Here Comes the Sun’ at Eric Clapton’s house in Surrey in April 1969. It was a month that enjoyed record hours of sunlight for the decade, following what meteorological experts would agree was a particularly “long, cold, lonely winter” in February and March. Harrison commented that: “It was all just the release of that tension that had been building up on me. It was just a really nice sunny day, and I picked up the guitar.” 

The sun certainly has an effect on us, even if there seems to be little, if any, link between sunny days and voting - despite the widely held view that a rainy day benefits the Conservative party in the UK, there’s no scientific evidence to support it. Indeed, one piece of research by politics and meteorological researchers at the University of Reading looking at voting statistics in the Wokingham constituency where the university is located indicates that right wing candidates enjoy a 0.5% swing in vote share for every degree it gets warmer.  

Exposure to sunlight also affects shoppers and tends to make their moods more positive. One company that tried to take advantage of this was Coca-Cola who in 1999 looked into vending machines that increased the charge for a drink the hotter the temperature rose during the day. It was not a popular move and the idea was soon abandoned. Research shows that exposure to sunlight makes us more likely to spend more which is why some shops use bright lighting to replicate a sunny day. In less commercial terms, there are also some indications that sunshine simply makes us kinder. Studies show not only that the amount of sunshine is a good predictor of the generosity of tips left for restaurant waiters and waitresses, but also that passers-by were more likely to help a researcher who “accidentally” dropped a glove on the ground while walking along a street on sunny days compared to cloudy days.

The sun also plays a major part in producing interesting weather conditions. When shafts of light break the clouds – often at sunset or during hazy weather – they can produce a phenomenon known as ‘Jacob’s Ladder’ or in some parts of the country ‘God’s Fingers’ (the official term is a little less romantic, ‘crepuscular rays’). The effect is caused by particles of dust or tiny water droplets scattering the light and making certain areas of the sky look brighter.

Sunset and sunrise (i.e. when the sun is near the horizon) are also the best times to see monochrome rainbows, the reds standing out while blues, yellows, and greens are scattered by a thicker atmosphere. Other rare versions of the basic rainbow include double rainbows (when sunlight reflects in a raindrop twice rather than once) and fire rainbows, ‘circumhorizontal arcs’ or simply ‘upside down rainbows’, formed when sunlight is bent through ice crystals in high cirrus clouds.

This is all very well, but the only really important question is, what is the best weather for drying our clothes? Using a washing line has various benefits, not least that it’s cheaper but also ultraviolet rays work well against stains, dust mites and bacteria. According to research by Jim NR Dale, founder of the British Weather Services, there is a winning formula for this key operation. The exact formula looks a bit frightening written down, but it comes down to requiring at least an hour of sun (full sun is ideal), under 70% relative humidity, temperatures above 21°C, and a sustained wind of 8-12mph.

Talking about the sun

Some sun-related terms have rather fallen out of favour, such as ‘foxy’ for sunny weather which is still a bit chilly, and ‘apricity’ which describes warm sun in winter. Here are some regional examples in regular use over the last two centuries:

* ‘The Devil is beating his wife/grandmother’, for when it’s raining but the sun is shining at the same time (Dorset/Somerset)

* ‘splitting the trees’ used when it’s boiling hot on a sunny day in Cumbria, the North East, or Scotland

* In Berkshire you might say ‘What be good for the hay be bad for the turmuts’, or what’s ideal weather for making hay (sun) is not great for growing turnips (rain)

* In the same county, ‘grawin’ is that sorry state of affairs when showers and sunshine are alternating. In East Anglia, the same conditions are known as ‘lecking’, in Essex as ‘following time’, and in Lincolnshire as ‘gleamy’

* ‘As red as the rising sun at Bromford’ is an old Warwickshire saying

* And in the wider West Midlands region, ‘When the sun shines on both sides of the hedge’ means ‘it’s never going to happen’

My book 100 Words for Rain: And everything else you need to know about British weather (National Trust Books, £9.99) is out now. A version of this article first appeared in the Daily Express earlier this year.