Tag Archives: Kew

London droughts back to 1871

A thunderstorm on July 27th has ended a dry spell that lasted nearly 7 weeks in east London. As storms go it was a fairly tame affair, just 1.3mm fell, the first rain in 47 days, 20 hours and 14 mins.

drought rankThere are many descriptions of drought but the one I am using here, for sheer simplicity of comparison back to 1871, is the definition used up until the 1990s; that is 15 consecutive days with less than 0.25mm (0.01 inches) rain on any one day.

Meteorological droughts occur in most years though obviously ones that occur in summer are far more noticeable than those in winter. Since 1871 there have been 35 calendar years where no drought has taken place.

The longest drought before this one in 2018, probably not surprising for those who remember it, occurred during the long hot summer of 1976. The fact that summer came on top of a very dry winter, rainfall that season was about a third of what was recorded here last winter, meant that water supplies were in a much worse state, with hosepipe bans common.

Other drought years to feature include 1959, which saw the 3rd sunniest summer on record, 1929 and 1995, a summer which saw one of the hottest heatwaves on record.

For the stats I’ve used local rainfall figures back to 1959 and then stats used at Kew to 1871.

individual droughts
This graphic shows droughts were most common between 2000 and 1921. Apart from this year the length of droughts seems to be declining

Looking at the results more closely I’ve divided them into their meteorological seasons.

spring drought

summer drought

autumn drought

winter drought

 

 

 

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August 10, 2003: UK’s hottest day ever

The UK’s hottest day was recorded on August 10, 2003, when temperatures across the south-east soared above 38C for the first time.

The weather station at Brogdale, the home of the national fruit collection, near Faversham, Kent
The weather station at Brogdale, the home of the national fruit collection, near Faversham, Kent

A study since then has uncovered that the 38.5C (101.3F) value may be anomalous after it became apparent that the Brogdale value was nearly 2C higher than nearby stations – a fact that would normally rule out such a reading. The actual site also leaves something to be desired with the leylandii hedge being too close to the met enclosure – and possibly helping up the temperature. Scientists are a fussy lot and like things to be done properly – believing that the figure of 38.1C recorded at Kew and Gravesend  on August 10 represents the true record.

But the Met Office refuse to budge and are sticking with Brogdale.

I recorded 38.4C in my own back garden – but because it is not an official site it doesn’t count. Other sites close by also set records that day: 37.9C was reached at Epping while another observer at Woodford Green recorded 36.5C at 2.30pm.

Being the weather anorak I am my memories of that day are still very clear. The birth of my first daughter was imminent and my wife and I were frantically trying to finish the kitchen of our house in Leytonstone. I’d borrowed a van off a mate that day to pick up kitchen units from the Stansted area. The old Renault Master didn’t have air conditioning and a faulty fan made the cabin feel like an oven. As we trundled back down the M11 from our trip to ‘You’re Furnished’ I wound down the window to experience what I can only describe as like being blasted with a hairdryer. Obviously anything above normal body temperature of 37C is going to feel warm  – the opposite of the windchill factor you get in winter. Somehow, through all the heat and pouring with sweat, we managed to unload the van at the other end and completed the kitchen.

screenThe day was the peak of the heatwave with just a couple more 30C days before, much to the relief of my wife, cooler weather arrived. Our daughter was born, over two weeks past her due date, on September 7. A sunny, fresh morning I’ll also never forget.

People often ask if it is possible that the record will be broken. Of course with the right synoptics anything is possible. And official records in the UK, and the world, are just a blip of what has gone before. Diaries of events during the July 1808 heatwave, mentioning accounts of people and livestock dropping dead in fields and birds dropping out of the sky, suggest that somewhere in Lincolnshire possibly saw the temperature exceed 40C.

44
44 UK stations recorded values of 30C and over

A report in today’s Express suggests that a heatwave could be on the way. Unless they are looking at a different set of charts I think the report is probably more to boost their sales – figures show that every time the paper splashes on the weather sales spike 10%.

While we may still see the odd hot day, as we did last Thursday when I recorded the year’s second-highest temperature of 33.6C, I don’t think we are going to see a sustained run of 30C plus temperatures. More *heatspike* than *heatwave*. August is likely to be average overall.

Scott Whitehead
@wanstead_meteo
http://www.wansteadweather.co.uk