GFS model forecasts near-record lows in the mid-30s (Fahrenheit).
According to the Washington Post, lows could dip into the 30s in the coldest parts of the D.C. metro region by Monday morning, and a bit of patchy frost is possible. The European model predicts lows of 40-45.
So far this month, on three days highs only reached the 50s, tying for ninth most on record (month-to-date).
And the average temperature for the month, in its entirety, is running 4 degrees below normal.
Following highs Sunday afternoon in the low-to-mid 60s, some 10 to 15 degrees below normal, temperatures may fall steeply overnight.
So much for global warming.
Thanks to Bill Sellers for this link