September juniper grafting in SF Bay Area?

I have heard that some bonsai enthusiast have had success grafting junipers in the SF Bay Area in September.
Any success stories out there?
I have had some success grafting in late January early February but want to give myself as much practice and chances for success as I can.
Thank you,

Hello, Are you referring to scion grafting or approach grafting for junipers. It might make a difference in the responses you receive.

Sorry, I should have mentioned scion grafting.

I will be curious to hear what people have experienced when they have tried it in the fall. Great question!

I’ve had the best success right at the end of winter. Theoretically, the best time to do side veneer grafts is when the host is active and the scion is dormant.

I too will be curious if anyone has good experience with scion grafts in fall.