1683–1684, "The Great Frost", when the Thames, hosting one of many River Thames frost fairs, was frozen all the way up to the London Bridge and remained frozen for about two months. Ice was about 27 cm (11 in) thick in London and about 120 cm (47 in) thick in Somerset. The sea froze up to 2 miles (3.2 km) out around the coast of the southern North Sea, causing severe problems for shipping and preventing use of many harbors.
