Out of interested i just had a look at the CET records to find other summers which saw a <14C to >17C transition (possibly one of the largest?) from June and July to see what August produced. Since 1950 only 3 summers fit the bill... 1999 (13.9, 17.7, 16.1) 1991 (12.1, 17.3, 17.1) 1955 (13.8, 17.7, 18.1) It seems then (if we include 1991 despite the June CET being well below) that there's a slight bias towards an above average August here however the most recent analogue is the coolest.