Surface observations

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

The weather observed at SAN FRANCISCO, CA (KSFO) at 02:56 AM PDT was:
  The skies were mostly clear.
  Temperature: 54F ( 12C)  Dewpoint:  46F (  8C)  Relative Humidity:  77%
  Winds from the NW (310 degs) at 12 mph.
  Pressure: 1011.3 millibars.  Altimeter:29.87 inches of mercury.
  The prevailing visibility was 10 miles.