Arlington, the District and other surrounding areas are under a Frost Advisory for Monday morning.
Forecasters say temperatures will dip to the mid-30s and could damage sensitive outdoor plants.
More from the National Weather Service:
…FROST ADVISORY REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 10 AM EDT MONDAY… * TEMPERATURES…AS LOW AS 35. * IMPACTS…FROST COULD HARM SENSITIVE OUTDOOR VEGETATION. PRECAUTIONARY/PREPAREDNESS ACTIONS… A FROST ADVISORY MEANS THAT WIDESPREAD FROST IS EXPECTED. SENSITIVE OUTDOOR PLANTS MAY BE KILLED IF LEFT UNCOVERED. &&
Frost advisories (immediate metro area) and freeze warnings (southwest of Fairfax and Loudoun County) Monday morning around the Washington and Baltimore region. Temps dropping into the 30s areawide. pic.twitter.com/fZI1R3EiJd
— Capital Weather Gang (@capitalweather) October 21, 2018