Arlington and other parts of the D.C. area are under a Frost Advisory tonight.
Temperatures are expected to dip into the mid-30s early Wednesday morning, potentially damaging sensitive plants.
From the National Weather Service:
… FROST ADVISORY REMAINS IN EFFECT FROM 1 AM TO 9 AM EDT WEDNESDAY… * TEMPERATURES… DROPPING INTO THE MID 30S BY DAWN, ESPECIALLY AWAY FROM LARGER BODIES OF WATER AND URBAN AREAS. * IMPACTS… A FROST ADVISORY MEANS THAT WIDESPREAD FROST IS EXPECTED. SENSITIVE OUTDOOR PLANTS MAY BE KILLED IF LEFT UNCOVERED. PRECAUTIONARY/PREPAREDNESS ACTIONS… A FROST ADVISORY MEANS THAT WIDESPREAD FROST IS EXPECTED. SENSITIVE OUTDOOR PLANTS MAY BE KILLED IF LEFT UNCOVERED.