Heavy snowfall remains a rare occurrence in west London, despite last week's blizzard-like conditions and predictions for another possible blanketing this week.

Even less frequent are instances of the Thames freezing over, as what happened during a freak cold snap early on in the Second World War.

In previous centuries, when Europe underwent a minor ice age, the river would freeze with regularity and Londoners would hold annual 'frost fairs' on the ice.

But the climate was changing in the pre-Victorian era, and January 30, 1940 marked the coldest month since 1791 and the first time the Thames had frozen solid since 1814 - the year an elephant was led across the ice beneath Blackfriars Bridge.

There were three inches of snow in the middle of the city, and conditions were certainly treacherous.

Widespread flooding was caused in February 1940 by the melting remains of the ice storm which affected a large swathe of southern England.

In the great freeze of January 1963 the upper reaches of the Thames froze again, although the hot effluent from two thermal power stations at Battersea and Bankside prevented ice from forming in central London.