November 1940 was the wettest on record for this area. Over 170mm of rain fell in Greenwich, beating the previous record set over a hundred years before in 1836.
Other areas of London were even wetter: Croydon was wettest with just under 196mm while Addington recorded just under 194mm, Bromley 179mm and Regent’s Park 175mm.
Nearly a quarter of the month’s rainfall fell on the 3rd. The total of 40.8mm is a daily November record that remains to this day. Indeed, throughout the month, there were falls of more than one inch (25.4mm) somewhere in the London area on four days: 40.8mm (3rd, Greenwich), 26.7mm (4th, East Ham), 26.4mm (11th, Camden Square), 27.4mm (13th, Southgate).
In Wanstead and Woodford the inclement weather coincided with a 6-day pause in bombing incidents during the Blitz. November was a very cyclonic month that probably hampered German air operations.
Another 6-day pause in the bombing happened after November 16th. When the Luftwaffe returned on Saturday, November 23rd, it was Wanstead that bore the brunt. At 4.12pm, as light was fading on a dull, dreary afternoon, high explosive bombs caused fires at and partly demolished nos 78 and 89 New Wanstead. A minute later another bomb ruptured water and gas mains in Spratt Hall Road. At 4.30pm a further high explosive bomb fell in the High Street, killing 4 people. The raid ended at 5.16pm as a bomb fell in Fitzgerald Road though this time there were no injuries.
By now the weather was beginning to quieten down though weeks of deep depressions with associated gales and heavy rain had taken their toll – many residents reported problems of Anderson bomb shelters being constantly flooded – but it was probably the design as much as the weather that was to blame.
As pressure built in the last few days of November the first frosts of winter arrived but the bombs returned. High explosive devices fell in Woodford New Road and Bunces Lane on the 30th, fracturing a water main.
To put November 1940 into some sort of perspective the average fall for the month in this area, with regard to the 1981-2010 average, is 59mm. The closest this area has come to matching the record was 2009 when 150mm was recorded and preceded a cold winter.
The following synoptic charts are for each day of November at 7am. All courtesy of the Met Office
Wanstead Meteo 
November 1940 is in fact the fourth-wettest month in the 250-year EWP series (behind October 1903, November 1852 and November 1770). There are some striking charts to go with all the rain, with low pressure over the UK and cold easterly winds over North Norway that did not affect the UK until well into the winter. The winter of 1940/1941 is the ninth-coldest of the twentieth century
It’s much less famous than the charts or figures would suggest, likely because 1940 had already proved such an eventful year in UK weather. There was the cold January – the first subzero month for 45 years – with the huge snow and ice storms late in the month, and the brilliant extended summer. June 1940 was the sunniest month of the century across the UK as a whole (June 1887 is the last month likely to rival it) and August was remarkably dry in the south. Large areas of London and the southeast were rainless for over 40 days from 29 July until mid-September.
British weather watchers often say 1947 caused the misconception that cold winters are followed by hot summers, but 1940 could certainly have contributed too. Besides being the sunniest month of the century, June 1940 was (with 1970, which in fact followed the ninth-coldest November to March since 1896) the hottest between 1859 and 1975. It’s notable that – despite the influence of Australian greenhouse gas emissions on the global climate – there were four hotter Junes in the nineteenth century (1846, 1826, 1822 and 1858) and three hotter in the eighteenth (1798, 1762 and 1775) yet only 1976 was hotter in the twentieth and none have been as hot since 2000.
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Thanks Julien. The series I use is the Greenwich series which is most local to me. My main motivation to compile it is that the local stats can differ vastly from EWP – as can CET – so I wanted as accurate a record as I could possibly get. Unfortunately the Greenwich series is only in print and hasn’t been digitised by Met Office.
You may be interested in another blog I wrote on the start of the Blitz which, of course, deals with that long dry spell and glorious summer. What I find fascinating is that the weather turned autumnal pretty much the same moment that the bombs started the rain down.
https://wansteadmeteo.wordpress.com/2015/07/31/75th-anniversary-of-the-blitz-in-wanstead/
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