I recall that there was a very cool pool of water in the North Atlantic between Newfoundland and the UK during 1972, one of the reasons that was used to explain why June 1972 was so cool. That had a particular cool May to September CET period, much cooler than we have had this year but this current period does look like the coolest since 1993. Interestingly there was an El Niño during 1972-73.