Daily averages for Phoenix in September:
http://www.wrh.noaa.gov/psr/climate/...=PHX&parm=Norm

I can't find anything about average dewpoints. For me, dewpoint is better at determining how comfortable it is.
For me:
40s is awesome, maybe too dry
50s is great
low 60s is good
high 60s is uncomfortable
70 is horrible

weather.gov has tons of info, if not always easy to find. It's the NOAA site, and where most other sites get their basics. The "graphical forecast" is awesome, as it includes dewpoint thru the day.

weather.com is ok..., but it certainly has the useful average stuff more easily accessible:
http://www.weather.com/weather/wxcli...66?from=search
Their numbers are slightly different for September, but about the same:
http://www.weather.com/weather/wxcli...6?climoMonth=9

Here's a decent Phoenix climate overview:
http://geography.asu.edu/cerveny/wxpart1.htm#dew2

I don't know how you do it down there. I'm dying up here in MA. I can't wait for ski season...

Mrs Khan and I drove out to Canyon de Chelly once (thru Navajo and Hopi lands), and it really is amazing land. The Anasazi cliff dwellings in Canyon de Chelly are mindblowing.

-Gren