Temps in Rocklands in mid-late September?

[gafac]

hey

Is it still bearable to climb during the day at all?

[GlennM]

Yes. There will be some hot days, but there are also hot days in july. There will also be lots of cool days. If you choose the right area you can still climb most days in Sep. The gallery at the pass is good for warm days

[Thermophage]

September is perfect IMO. Often super super cold days and even the "warm" days are very very far from unbearably warm.