In article , Dan
writes

I thought there was enough food available to them during the summer
months?

Summer months aren't necessarily as good as they seem. There'll be
insects, but it takes longer for the seeds to come in. Birds have more
pressures on them with nesting and feeding young, then after that
they're moulting.

When I looked at the advice a few years ago, it seemed that if you want
a break from feeding, Sept-Oct is probably the best. That said, they are
still making really good use of the feeders.

--
Kay