I've experienced the July heat in Madrid but I am going there in the first week of September and wondered what sort of temperature to expect. My guide books are a little vague but I assume that temps around mid seventies or so could be expected.
Any other info?

You´re right, about my temperature records the daily highs of september arounds 75 F. (27ºC), the lows are still soft (14ºC-19º), but everybody knows that it´s impossible to know what will the exact temperature.The sun is more pleasant!.

Deal is this: Madrid CAN be really hot in September, but usually isn't.The sun sets earlier, so even if you get that diurnal 38, you'll have a nice nocturnal 22 for good sleeping. September is usually glorious!

sounds like just the place. Thanks for the help.