The weather observed at WASHINGTON DC, VA (KDCA) at 12:52 AM EST was: The skies were mostly cloudy. Temperature: 35F ( 2C) Dewpoint: 19F ( -7C) Relative Humidity: 52% Winds from the CLM(CLM degs) at 0 mph. Pressure: 1026.5 millibars. Altimeter:30.32 inches of mercury. The prevailing visibility was 10 miles. The maximum temperature in the past 6 hours was 37F. The minimum temperature in the past 6 hours was 34F.