7:30 pm -- down to 37° in Columbia, east side. Nice temp drops, as others have reported. Skies mostly clear. The cold air arriving just in time, just ahead of the moisture .... for a change. I did notice on a live TV DC shot on (probably a cable news channel or maybe Redskins game), it looked like a few clouds were scattered around DC in late in the afternoon.
For any one in DC: did those clouds clear up, or ..... ??
(trying to compute about how many more good hours in Columbia we may have for temps to keep falling before increasing clouds slow up the downward trend)