I walked during July-Aug of 07, so I voted for July. I don't mind the heat - indeed, I prefer it to cold, rain, or darkness (snow might be interesting, though). Plus, I liked the long sunny days for a number of reasons: plenty of time for the laundry to dry, ability to dress light, agreeable weather for city exploration, no problems lounging around outside of cafes, less likely to slip & fall on the hills, better visibility on the roads (more so for cars to avoid me), got to work on my tan, etc.
But I did experience some scuzzy weather during those months - it rained the day I walked into Logrono, and one of my hardest walking days was when I climbed up to/headed down from O'Cebreiro - windy, foggy, and rainy. The hard weather did give the area some atmosphere, though - it made me feel like I was in an old Hammer vampire movie. I kept expecting to see Peter Cushing chasing Christopher Lee around with a stake in his hand... :wink: And it was kind of a good personal challenge walking in it as well. It sure made the cafe con cognac and hot food taste better during my break periods. :arrow: