In Southern France, almost three weeks back now, they had a few 40c days and our friends shared that experience with us, as their property has a lot of trees, they mentioned that you could smell the leaves cooking in the heat of the sun which left a rather pungent odour on the air. it was also very evident when we first arrived on the 31st August as most of the nut trees have dried, crispy leaves which they are now shedding and the fruit trees and most noticeably their cherry, were all wilting and leaves curled. There was overnight rain on the 2nd September which seemed to briefly refresh most of the trees and plants but by the time we were leaving yesterday they were all looking a bit sad as it's been hot and dry all week again. Hopefully it will rain there on Tuesday.
One other note is that this year there has been bumper nut harvests from their hazelnuts and walnuts and all their fruit trees too. But a noticeable lack of so many wasps, in comparison to the last five years, they had a longer and colder winter earlier and a good amount of snow which may (or not) have been a contributing factor.