I've been hearing and/or seeing one to two Common Nighthawks over my apartment bldg on Q St NW, near the Dumbarton Bridge, for the past few weeks.  If I'm out in the hour or so before sunset, or shortly after, I'm sure to see or hear at least one.  They always appear to come in to town from the west.
--
Carrol Cowan 
Washington DC 
arielamcATatt.net