Did the Thames really used to freeze over?

History Extra

The London Frost Fair, 1683-84, by Thomas Wyke

With the Sun shining and summer on its way, it’s hard to imagine that the mighty river could ever fully freeze over.
This article was first published in the April 2015 issue of History Revealed

Yet, the Thames froze at London at least 23 times between 1408 and 1814, though several of these events lasted only a few days.
The freezing of the river, where ice is now rarely seen, was caused by three factors. First, the climate in Britain was on average about one degree (Celsius) colder between about 1400 and 1800 than before or since.
Second, the Thames was then wider and shallower than it is today, as it is now restricted between solid embankments.
Finally, the numerous narrow arches of the medieval London Bridge partially blocked the water on the upstream side, reducing the flow.
During the big chill of 1683-4, the Thames froze for two months, with ice some 28cm thick. This provided a pleasant cold comfort for Londoners as the Thames became a stage for the most famous of the London Frost Fairs. The frozen festival featured horse racing, bear-baiting and puppet shows – all on the ice. It was described as a “carnival on the water”.
Answered by one of our Q&A experts, Rupert Matthews. For more fascinating questions by Rupert, and the rest of our panel, pick up a copy of History Revealed! Available in print and for digital devices.