In reply to Harry Chaplin:
Your choice of where to spend a month-long sport climbing trip to Spain in June might actually be more dependent on your lack of personal transport than the climate.
Of the top of my head only a couple of places fit the bill: Siurana and Rodellar. Both have public transport links from major towns and both offer accommodation options from where it is possible to walk to lots of different sectors in under 30 minutes.
Rodellar is the acknowledged premium summer destination, but only if you climb 7b or harder. Below that you will be struggling to find enough to last a week, let alone a month.
Siurana is certainly an option: there are several major sectors getting shade until early/mid afternoon (Onassis, Can Codolà, l'Aparador) as well as one or two others providing afternoon shade (Siuranella Nord being the most popular).
Far more hot weather choices are available in Lleida province (northwest Catalunya) but most are unviable without a car.
Pete.