When to visit Rishiri/Rebun?

Having hard times visiting Japan during summer months but wishing to visit Rishiri Rebun Islands, when would be best months to visit? I mean, when does it not snow?

I do not plan on climbing the mountains as it looks too tough.

Very Late July / Early August

@Moh, what do you mean with “Having hard times visiting Japan during summer months ”?

You don’t have time in summer to travel to Japan? Or your previous experience in summer in Japan was bad and thus you don’t WANT to travel to Japan in summer?

As @mefley was saying July/Aug on these islands would be ideal. And Hokkaido in general is good at that time. Or even a bit earlier and also a bit later. I’d say Hokkaido in general might be ideal between June and Mid October. Roughly speaking. Those northern islands better in the hight of the summer.

Well I would say it is harder to have my vacation accepted by work at summer months, and since I like to enjoy summer where I live too.

Hence going in sept-october would be easier. But if visning the islands in autumn is not that good I might try to go in August maybe.

When to expect snow there by the way?