That's interesting - although there's not the Armageddon type conditions in Europe and north America that i'd expected, they are still breaking heat records - several more fell this week. Was also the hottest June on record for Europe.

https://www.theguardian.com/world/2019/jul/24/summers-second-heatwave-set-to-break-reco...

We'd need to know more about how the weather patterns work to properly analyse the situation in Japan - could it be that the 'omega block' referred to in the above article - "a high-pressure pattern that blocks and diverts the jet stream, allowing a mass of hot air to flow up from northern Africa and the Iberian peninsula " (causing the extreme heat in Europe), somehow be having a cooling effect in Japan?