"cool" "dry" is actually fairly technical. "Room temperature" is ~72deg F (22ish degrees C), where "Cool" is 55ish degrees Fahrenheit (14ish degrees C) and "dry" is below an average of 60% relative humidity. Or at least that's the standard nomenclature in both data centers and wine cellars.
In science, "room temperature" is generally defined as 20-25 deg C (somewhere around 68-77 deg F), but it's not an SI or STP unit - so presumably "cool" is below that.
My home server room is about the ideal place for "cool dry" in my opinion. The AC is set for 62 deg and 55% humidity. So it ranges < 64 deg F and from 45-60% humidity. I also keep it in the safe, which is insulated, so it meets the "cool, dark, dry place"... (the real data-center is set for 57deg F and runs 54 - 62 deg F, 60% humidity)
Anywho - that's how the "definition" has been explained to me in various fields of study. Given the overlap betwixt them all, it seems as good as an "inch" or "foot"
