Poor Augusts in the last century
Whilst it is always pleasant to have a fine dry August there is a good chance that it will not live up to our- possibly- rather heady expectations. This was certainly the case almost 100 years ago in 1912. This month stands out as an exceptionally poor month even by other poor August standards. It was the wettest (231%), dullest, and the coldest (12.9C CET) of the century. As this is the only month that holds all three worst records, as Dr Trevor Harley points on his excellent 'British Weather' site (http://www.personal.dundee.ac.uk/~taharley/britweather.html) it is undoubtedly the worst summer month in the last century. For example there was just a single day all month in London when the mercury rose above 70F (21C) and plenty of days when it didn't make 60F (15.5C) even.
It is notable for the 'Great Norfolk flood' event on the 26th when 206 mm fell at Brundall in 24 hours and the pressure as low as 978mb at Great Yarmouth with gale force winds. Here is the weather chart for that day http://www.wetterzentrale.de/pics/archive/slp/1912/Rslp19120826.gif as the low was filling up. Norwich was cut off for two days, with over 40 bridges destroyed and the flooding 15 feet deep in places and in fact parts of the Fens stayed under water throughout the following winter.
During the First World War the August of 1917 cannot have helped boost morale either; this was the second wettest of the century. It rained for a solid 53 hours at Canterbury (Kent) with 144 mm of rain the week up to the 4th at Margate (Kent). The pressure fell to 967mb on the 27th at Nottingham, which remains a record low for August -and it kept on raining. Another 50 mm of rain fell on the 27th over Wales and the southwest; giving as much as 228% of the average by the months end across Wales as a whole and 194% over England. The rain caused the legendary mud on the other side of the Channel - in particular the battle of Passchendaele became synonymous with the awful grinding attrition of warfare fought in thick mud, the newly-developed tanks became hopelessly bogged down in the deep mud, and soldiers often drowned in it.
Then 1920-1925 was a period characterised by dull wet Augusts too, though to be fair there were some short lived hot periods in places. August 1931 was another wet, chilly month, with some notable downpours. It was quite thundery too in fact with regular thundery periods across England early on. Steeple Langford (Dorset) had 114mm in 135 minutes and there were severe storms too over London on the 5th. Boston (Lincs.) had 100 mm in two hours on the 8th. At least the far north fared better though.
The second half of the 20th century had its fair share of drear Augusts too. 1956 in particular was one of the coldest (with at CET 13.5C) and also the wettest of the century as low pressure dominated. The August bank holiday was early then and the 6th was one of the worst Bank Holidays on record. Severe thunderstorms and hail caused flooding in Tunbridge Wells (Kent) with drifts of hail a staggering four feet deep in places and places saw temperatures struggle to rise about the low 50's F. Locally then -in the northwest- August 1956 became the wettest month so far of the century.
The period from 1960-1966 was characterised by fairly awful August's too. This was when I was growing up and I well remember holidays spent in Wales and Devon in unrelenting showery rain, when we would grab any beach time with open arms, buckets & spades. I think I was so young then though that I just thought it was always like that in August! 1967 started hot but soon degenerated in a mixture of thunderstorms and heavy rain. After the notably dry hot Augusts of the early to mid seventies, 1977-1980 were again rather poor. In particular 1986 was a stinker. It was both chilly (the CET of 13.7C was the lowest since 1956) dull and wet, with Hurricane Charley's remnants putting paid to the late August Bank Holiday on the 25th.See http://en.wikipedia.org/wiki/1986_Atlantic_hurricane_season#Hurricane_Charley. In fact it is still the wettest August Bank Holiday on record, with 50 mm of rain over Wales, the Midlands, and the north of England and as much as 135 mm recorded at Aber in north Wales. There was widespread flooding and problems caused by the trees in full leaf brought down by the high winds. See also this thread about it at UK Weatherworld http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=4173&posts=6
August's were certainly better overall in the 1990's, we got used to expecting warmth and sunshine but 1999 was a notable exception. It was both wet and thundery across England and Wales, the wettest since 1992 and probably the most thundery August since 1960. There were some severe storms and local flooding during the month for example the 1st saw Chorley (Lancs) report 50mm of rain in just 2 hours and floods from a storm closed the M9 in Scotland. Later the 8-9th was wet with Windsor reporting 117mm of rain and Coventry 60mm. Then more recently there was the pretty wet August of 2004 in fact the wettest August since 1956. However- to be fair- this wasn't a cool month , in fact it was quite hot overall (17.7C CET). There were lots of thunderstorms though and the 9th-11th saw notably heavy rain in central /southern Scotland and northern England. Aberfeldy saw nearly 150 mm in three days. More exceptionally heavy rain in Cornwall on the 16th with the Boscastle flash flooding event and central Scotland seeing mudslips bury cars on the A85 and A84 near Lochearnhead. Another thundery month-taking the crown from 1999- to become the most thundery August since 1960.
So, all in all, we really should hope for the best with August as a summer month. It holds great promise in theory but all too often fails to deliver the goods. Too much heat and we get torrential rain and thundery breakdowns, too little and it just feels dank and moist. Don't be too surprised if August 2010 is a bit of a washout. It remains par for the course!
Kind thanks are due to Dr Trevor Harley and his excellent site 'British Weather' for the use of some of the data used in this article http://www.personal.dundee.ac.uk/~taharley/britweather.html
