Rebun/Rishiri in June/July

Hi.
Thinking of visiting the 2 islands next summer 2022.
Is end June or early July a better time to visit the islands ?
Is early July considered the start of the peak tourist season or ?
Thanks.

Is end June or early July a better time to visit the islands ?

It doesn't make a difference. They are equally nice and come with an equal chance of sun and rain (about 40% sunny days vs. about 25% rainy days).

Is early July considered the start of the peak tourist season or ?

The start of the peak tourist season is around July 20 when the school holidays start.

Thanks Uji, always good to hear from you.

I ask about July as a peak travel period because I noticed ANA (as an example) has some sort of blackout dates on their special Visist japan fare for foreigners from 1 July - 31 August.
Could it be because the July/August period is considered peakmost tourist season.
But guess you have answered my question there.
Thanks.

Could it be because the July/August period is considered peakmost tourist season.

Yes, that is the reason.

We visited the islands twice: the first time was in late June, the weather was perfect then, but too early for "the flowers". We revisited the following year in late July, hoping a perfect timing to see "the flowers" and expecting better weather. Unfortunately, the Rebunto was covered with fog for three days, a rather unexpected experience.