I’ve mentioned it before, but hesitated to bring it up again, as I didn’t want to whine about it 
I checked and the exact count was 0 in 109. It hurts a bit, but I suppose that is how you learn.
It hurt enough that I would encourage you to go out and put a few grafts on tomorrow. That gives them a few days before the heat hits and 3 of the next 4 days are close to 60F (57, 51, 61, 61). I’m not sure if your forecast is the same as mine, but it is probably close given our proximity. Tuesday is OK at 72 (though very sunny, so black electric tape could get pretty hot). Wednesday and Thursday get up to 77 and 83, which is getting close to the territory I was at with my failures last year.
It definitely saves time when you go out to graft. I’ve taken to prepping the night before (including labels, etc), as I have limited daylight hours for the actual grafting. I need to look at what I have left. I’m hoping to finish up everything but persimmons.