Quote Originally Posted by JerMc
It's also possible on the Centegrade scale. The only temperature scales that I know of where 30 below zero in not possible are Kelvin and Rankine. Both of those are based not on the freezing point of water but on "absolute zero, which is defined at the temperature at which all molecular motion ceases. On the Kelvin scale, water freezes at 273 deg, and boils at 373 deg.
You had better believe it is. I remember many a Manitoba winter where -30 C was the norm for weeks on end. It really makes me appreciate the fact that I am now sitting in a climate in shorts on Dec. 23rd.