Surface observations

Data from the National Weather Service, made available here by the UAlbany Department of Earth and Atmospheric Sciences

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.