I have seen -40F in Flag and i personally recorded an official -30F reading at Wupatki Nat'l Mon, about 3,000 feet lower than Flag. One Memorial Day weekend it was snowing in Flag and I was thinking "Good grief! I have seasonal rangers reporting for duty in about a week and they will be wearing short sleeve shirts..." Not to worry. Temps were very soon in the 80s and 90s....

It's country and conditions like that the get you in the habit of keeping a sleeping bag and a few other goodiesin the vehicle - always.