On 2nd February 2009 much of London had the deepest snow for 18 years. Depths of level snow of around 20cm were commonplace with considerably more in the southern suburbs and towards the North Downs in Surrey. Around Epsom, Leatherhead and Banstead, over 30cm was recorded. This was the greatest depth locally since December 1962. Central London’s 15cm compares with 20cm in February 1991.

How do these depths compare with what London has experienced in past centuries? The best source of information on London’s weather prior to the mid-1960s is an excellent book called (somewhat unsurprisingly) ‘London Weather’, by J. H. Brazell and published by HMSO in 1968).  

Before the 19^th century, reports of snow depth were scarce; historical accounts tend to refer to the spectacle of the Thames freezing, a phenomenon we are not likely to see in our lifetimes. By the early 1800s we start to find records of depth measurements, although a degree of exaggeration may be involved in these earliest reports. A five-day blizzard starting on Christmas Eve in December 1836 reportedly gave drifts of 12-40ft (4 to 12m.) and the 19^th century equivalent of traffic gridlock. A drift of 8ft (2.4m.) in Regent Street is beyond our comprehension but this is what was observed in the next major snowfall, on the last day of 1866.

London was not spared in the great blizzard of January 1881. This was associated with an eastward moving depression that forced the snow to blow in strong easterly winds. A level depth of 9 inches (23cm) gave drifts in London of 3 to 4 ft but in Kent drifts reached 10ft (3m.) More remarkably, there was a report of a drift of 15ft at Oxford Circus – about 4.5 metres!  Road and rail traffic was seriously disrupted for over a week.

In the 20^th century, the cold winters of 1947 and 1963 both had some heavy snowfalls but one of the other most remarkable blizzards was that of Boxing Day 1927. Once again, the snow fell with easterly gales and drifted to 15ft in places. Not surprisingly, 42 cars were abandoned at Westerham on the North Downs in Kent. When we take account of the much greater volumes of traffic on our roads in the South East today, I wonder how many cars might get stuck in a similar depth of snow were it to happen again. Local history and weather books contain a wealth of photographs of cars being dug out of deep drifts on this and other occasions in the early 20^th century.

These past examples show that for really widespread, deep snow in the South East we need easterly winds, sometimes associated with a depression moving east up the English Channel. This has been a rare event in recent decades – although something similar may happen on Monday 9^th February. However, it remains to be seen whether the air around a depression moving in from the Atlantic will now be cold enough to produce widespread snow as opposed to rain.

Julian Mayes

MeteoGroup UK

This entry was posted on 13.02.09 and is filed under . You can leave a response, or trackback from your own site.