The long forgotten remarkable droughty summer of 1800

[Isle of Harry]

Around 219 years ago, back in 1800, May opened up with a pleasant burst of early summer-heat but June began cooler and was dull with cloudy and wet conditions and perhaps the locals were gearing up for another typical British summer - but what was coming up was nothing short than extraordinary. From the 23rd June to 23rd August no rain fell - it was hot, dry and clear with blue skies for practically two months (62 days - just under 9 weeks) .

Temperatures in July remained in the mid to upper 20's every day and were sunny and clear. The high amount of heat and the dryness of the atmosphere would probably have made conditions very oppressive in London at that time, the jet streams most likely parking anticyclonic pressure over Great Britain and staying there for weeks on end, dragging up tropical air from the equator in a ''Spanish plume'' effect maybe? There was no relief from this heatwave from July into August as temperatures soared into the low 30's (maybe higher?), even the nights were very warm and humid with 25C recorded just before midnight on the 2nd August. The long heatwave and the general sultriness continued till the 23rd August when finally some showery weather returned with some relief but what an incredible Summer this was and totally the opposite of the fairly cool and wet summer of 1799. 

Data is from B.W Cary's stand in Central London - so there may have been different conditions in the North or out to the far west but It's probably a clear indication of what was going on in the southeast. I'd imagine though the heatwave probably did effect large areas of the country regardless. 

 

 

[Summer of 95]

Looks amazingly similar to 1995; the hot start to May followed by a sharp cooldown, pretty lousy late May and first half of June, then flipped about 20-25 June to warm dry weather which lasted through to late August.

http://climate.armagh.ac.uk/scans/1800/07/INDEXA.html

http://climate.armagh.ac.uk/scans/1800/08/INDEXA.html

But regarding the rest of the country, the records from Armagh observatory suggest it wasn't anywhere near as good up there, unlike 1995 which was as exceptional there as anywhere in England. Lots of comments saying "clouded", "light rain" etc despite the odd day having "fine summer weather". While at London the pressure never fell below 30" ( about 1016mb) from 4 July to 19 August, at Armagh it was regularly below, sometimes well below (29.5"=1000mb) except for 19-26 July which seems to have been the best spell of the summer. Lots and lots of W and SW wind directions at Armagh too, combined with the cloudiness and fairly warm temperatures suggest the high pressure was centered mainly over S or Central Britain, with the North of Ireland getting gunk-laden west and southwesterly winds coming round the top of it. I'd imagine that England and Wales had a fine summer, except possibly Cumbria; but Scotland not so much.

[Isle of Harry]

Interesting information there! I was only 5/6 years old during the 95/96 very hot and dry summers so I don't really remember much 

This 1800 summer heatwave pretty much kicked of series of very hot and dry summers especially 1801, 1805, 1806,1807 and 1808. A decade very much in contrast to the wet and fairly cool summers of the 1790's. 

As you can see in the table below average summer temperatures rose over 1 degree between the 1790's and 1800's. 

[Isle of Harry]

Try to find some reports on the 1800 drought from local newspapers at the time. Proved difficult but managed to find 4 quotes all from August 1800. I have also found an image of the Drought effects and it's extent from the Old World Drought Atlas.