Baltimore, Maryland — Chilly air is settling across Maryland and the D.C. region tonight, with temperatures dropping to 28 to 32 degrees in colder inland areas between 3 a.m. and 7 a.m. Sunday, creating frost and freeze conditions that could damage plants and cause slick spots on early morning roads in Hagerstown, Frederick, Westminster, Baltimore and Washington.
According to the National Weather Service in Baltimore/Washington, the coldest readings will occur away from urban centers, particularly in valleys and rural areas where temperatures fall fastest before sunrise.
This is part of a broader system bringing below-normal temperatures across the Mid-Atlantic, allowing cold air to settle under clearing skies and light winds.
Frost may form quickly on bridges and overpasses along I-70 and I-81, as well as in low-lying roads and rural drainage areas where cold air pools. Thin frost can reduce tire traction, especially in shaded spots during the early commute.
Sensitive vegetation is at risk of damage after several hours near or below freezing, particularly in outlying communities.
Drivers should slow on elevated roadways early Sunday, and residents should cover or bring in plants to prevent cold damage.
The most critical freeze window will occur between 4 a.m. and 7 a.m. Sunday, when temperatures bottom out across inland Maryland.
