Northern NM, as we have in CO, can vary dramatically so I think anyone would be challenged to give you many specifics this far out. A quick survey of September averages for Cimarron shows that you could have temps anywhere from 40-80F. As you probably know, adding some precip in that mix changes the calculus quite a bit. I think you'll probably find that you could have the most spectacular weather ever (mild, dry) or just the opposite. Attached is a photo at PSM in early October... Simply beautiful... Hope this helps some...