Well, after just three days of temperatures above 30° all my deciduous and tropicals stopped growing.
Some old leaves have dried and have fallen, new leaves hardened off, and it seems the main trigger is the afternoon sun.
It happens every year.
Have you had the same experience?

Yup. For a few weeks to maybe a month in summer I get a growth stop. Especially when it is hot and dry. Then when the rain begins to fall when the rains begin to fall , it is like a rainbow in the sky: A miracle, and all trees start to sprout. Of course, if I swith on my midday irrigation during this time, they seem to ignore the heat.

Not just the bonsais but most of the deciduous trees, dogwoods, maples, etc.

I had a student from Sao Paulo who said the weather here was very much like there, except off by six months.