The forecast minimum for Fort Collins on Saturday is -1F, which would be the first November 15 below 0F ever recorded there. From my experience, temperatures usually come in several degrees colder than forecast there during Arctic cold snaps.
The warmest November 15’s were 1981 and 1949.
Experts say that below zero temperatures almost never happen any more, due to your SUV. Look for NCDC to report 2014 as the hottest year ever, during the coldest mid-November on record.