The weather observed at MADISON, WI (KMSN) at 12:53 AM CST was: The skies were clear. Temperature: 37F ( 3C) Dewpoint: 26F ( -3C) Relative Humidity: 64% Winds were calm. Pressure: 1019.5 millibars. Altimeter:30.09 inches of mercury. The prevailing visibility was 10 miles.