It's very cold in the upper and lower Midwest right now. How cold can it get on a long-term basis and still support a functioning human population? For the answer, go to Oymyakon.
Oymyakon, in Russia’s Siberian republic of Yakutia, is the coldest inhabited place on Earth. The village of Oymyakon (???????) only has a population of 800 people and has registered a record low of 71.2 degrees below zero in [img_assist|nid=22657||desc=|link=none|align=left|width=246|height=185]1926. Average highs in winter are only -20 to -40F. Reports have it that it's so cold in Oymyakon that some birds freeze to death in mid-flight. The name Oymyakon actually means non-freezing water, because there is a natural hot spring nearby. The town is located 690 meters above sea level and lies in a valley between two mountain ranges (the reason for the low temperatures). The town was founded by the Mongol horsemen of Genghis Khan sometime in the 13th century.