In reply to Joaopacheco:
I highly recommend the sport climbing in and around the Picos De Europa, where it's often a bit cooler than the rest of Spain.
http://rocaverdeclimbing.com/?page_id=96
San Fausto in Navarra (near Pamplona) is excellent for climbing in the 6s, and I seem to remember has reasonable shade from about midday onwards.
As good as Riglos is, it will be very hot in August (this year seems warmer than previous years), and not much fun with just a single 60m rope, as many of the descents involve a fair bit of abseiling.