Longer evenings means that an evening trip to Rhayader area is on the cards. I've got the guidebook, but would be interested to hear which of the crags locals would recommend for a first visit.
Looking for sports routes up to 6c and trad to HVS
Craig Cnwch, the crag on the other side of the first dam (Caban Coch) has a mix of sport and trad climbing that fits the bill. Catches the summer evening sun too. Should you be tempted to visit Cerrig Gwynion (Rhayader Quarry) be aware there is now a very large new spiky gate and sturdy barbed wire to prevent access.
The guidebook's clear on the various options IMHO. There's only the one crag that's been bolted and for an evening visit, it'd have to be either Craig Caban Coch or Cerrig Gwynion for trad at the specified grade.