People were ice skating on the Thames river (which was never before seen to have frozen, even in winter), glaciers in the Alps advanced, and the entire
Dutch fleet of ships was frozen in its harbor.
The use
of canvas buckets by the
Dutch, Japanese and some UK
ships is most likely to blame, and given the mix
of national
fleets shown above, this will make a noticeable difference in 1945 up to the early 1960s maybe — the details will depend on the seasonal and areal coverage
of those sources compared to the dominant US information.