Frigid air gripped much of the nation from the upper Mississippi Valley across the lower Ohio Valley. The early morning temperature sank to 21 degrees in Chicago, shattering the 63-year-old day record by 2 degrees. At International Falls, Minn., 3 inches of snow fell and the temperature plummeted to 2 degrees, the lowest in the nation and breaking the city’s 1986 record of 13 degrees. A low of 20 degrees at Ft. Wayne, Ind., broke the city’s low temperature record for the date and tied the record for the month of October. Other records included 10 at Duluth, Minn.; 18 at Grand Rapids, Mich.; 18 at Jackson, Mich.; 11 at Rochester, Minn., and 13 at Madison, Wis.