Over the years significant weather events have, at least in my subconscience, at times signalled that something ‘big’ is about to happen – just one example being the Great Storm in October 1987 that was followed days later by the Black Monday stock market crash.

So an event that happened 100 years ago this month, to some, probably also brought a feeling of impending doom as the political situation in Europe became ever more fraught.

A series of severe thunderstorms that broke out just after midday over south-west London on June 14, 1914, left people dead and a trail of destruction across areas south of the Thames. Fierce lightning, torrential rain, severe flooding and hail ‘the size of walnuts’ accompanied the storms. Six people were killed by lightning on Wandsworth Common and four others were injured. As with many thunderstorms the heaviest rain, 94mm in 3 hours at Richmond Park, was focused over a small area. South Kensington, just over 5 miles away, recorded just 6mm! I don’t have the figures for Wanstead but judging by the map published in the 1914 edition of British Rainfall it probable recorded even less than South Kensington.

Some reports by observers.

Dulwich: Violent hailstorms. Many hailstones were like acid tablets about one inch long, half an inch broad and over a quarter of an inch thick. A minute or two after these had fallen, a mist rose to a height of about 4ft above the ground.

Lewisham: A storm began at 12.24pm and came right overhead from the east with terrific flashes of lightning and loud thunder. At 12.31pm, rain fell with extraordinary fury; within 9 minutes 0.5 inches had fallen. The second storm came up just after 1pm, the lightning being even more severe. At 1.30pm, St Mark’s Church, and the Holy Cross were  struck. A tree in Hither Green cemetery over 30ft high was splintered and two houses were struck at Catford. Another thunderstorm came up at 2.25pm with torrents of rain and hail as large as haricot beans fell for 5 minutes.

Richmond Park: Very severe storm passed over the house; an oak fence was struck by lightning in two places. Rainfall measurements were as follows: 1.80 inches in 45 minutes, 2.70 inches in 90 minutes, 3.2 inches in 2 hours, 3.60 inches in 2.5 hours, 3.70 inches in 2.75 hours.

Wimbledon Downs: There was a curious scene close to Kingston station, where the water was about 4ft feet deep at five o’clock and motor cars and omnibuses had to make a wide detour. The storm was especially severe in Wimbledon district, where, owing to the bursting of an overtaxed sewer, the District Railway line was submerged. At Tooting Junction station was a foot deep on the platform.

Judging by the 1881-1910 average 1914 was a warm year: the mean temperature of 10.7C  was a full degree warmer than average. It was also 15 per cent wetter than average and the sun hours were nearly 108% of average. Of course by today’s standards (the 1981-2010 average) 1914 looks relatively cool as the average annual temperature has risen 1C in the past hundred years.

The weather on this day must have been synonimous with the deteriorating political situation in Europe: two weeks later Franz Ferdinand, Archduke of Austria, and his wife Sophie were assassinated in Sarajevo by a young Serbian nationalist Gavrilo Princip , the casus belli of the First World War.

What is fascinating is that a similar thunderstorm that left seven dead in Valentines Park, Ilford, 75 years ago this August, also happened about two weeks before Prime Minister Neville Chamberlain announced on September 3, 1939, that Britain was at war with Germany.