From the Western Regional Climate Center:

"The highest temperatures in Colorado occur in the northeastern plains, and sometimes exceed 115° F. Because of the very low relative humidity accompanying these high temperatures, hot days cause less discomfort than in more humid areas. The usual winter extremes in the plains are from zero to 10° F or 15° F below zero."

From Wikipedia, "Coffea arabica": "The plant can tolerate low temperatures, but not frost, and does best with an average temperature between 15 and 24 °C (59 and 75 °F)."