What was the coldest windchill ever seen in Minnesota? The answer can be a little tricky because on November 2001 the formula on how to calculate the windchill was changed. Perhaps the coldest windchill the Twin Cities has ever seen was -67 with the new formula (-87 with the old formula) back on January 22nd 1936. The temperature was -34 with a wind speed of 20 mph. Without a lengthy state-wide wind record, it is difficult to say when was the coldest statewide windchill. There are some candidate dates though besides January 22, 1936. On January 9th and 10th, 1982 temperatures of -30 and winds of around 40mph were reported in Northern Minnesota. This would translate to -71 by the new formula (-100F by the old formula.)
What about the highest heat index ever reached in the Twin Cities or Minnesota? The heat index is a "feels like" measure which factors together temperature and dew point. The highest heat index value ever recorded in the Twin Cities is believed to be 119 degrees, occurring on July 11, 1966 (our thanks to climate historian Charles Fisk). For Minnesota, an air temperature of 97 degrees teamed with an 84 degree dew point to create a heat index value of 125 degrees at the Red Wing airport at 3:00 pm on July 30, 1999.