We went the end of September last year and it was too hot ! The friction dependent climbs were much harder as a consequence. You could see the rubber softening and folding under your weight. We found shaded slabs and it felt a lot more secure. We spent about 4 days there out of ten, the rest at the fantastic patones which is well worth the trip on its own. But that's a completely different style, more your traditional Spanish limestone. I want to go back to la pedriza it's a beautiful place and those slabs are insane ! It'll be March though !