The weather observed at MADISON, WI (KMSN) at 11:53 PM CDT was: The skies were clear. Temperature: 41F ( 5C) Dewpoint: 41F ( 5C) Relative Humidity: 100% Winds were calm. Pressure: 1028.6 millibars. Altimeter:30.37 inches of mercury. The prevailing visibility was 10 miles.