The weather observed at MADISON, WI (KMSN) at 02:53 AM CDT was: The skies were mostly clear. The weather reported was fog. Temperature: 61F ( 16C) Dewpoint: 61F ( 16C) Relative Humidity: 100% Winds were calm. Pressure: 1013.6 millibars. Altimeter:29.94 inches of mercury. The prevailing visibility was 5 miles.