The D.C. government activated its emergency plan for cold weather on Sunday night, as falling temperatures and rising winds were expected to produce some of the most dangerous conditions of the winter.

The plan was expected to stay in effect at least through Tuesday morning, said Laura Zeilinger, director of the Department of Human Services.

Meanwhile, the season’s first measurable snow fell Sunday at Reagan National Airport, 0.3 inches. Sunday was relatively warm compared with the high of 26 predicted by the National Weather Service for Monday.

Sustained winds of at least 20 mph were expected through 11 a.m. Monday, creating the potential for hazardous wind chill indexes.

Under the city’s cold weather plan, services provided include access to emergency shelter and overnight warming sites. Designated public buildings may open at night to offer access to a warm, safe place.

In addition, free transportation to a shelter or warming site is available to anyone homeless in the city during a cold weather alert.

City officials said transportation may be obtained by calling 311 or the toll-free Shelter Hotline: (800) 535-7252. The numbers may be used by third parties to seek help for those appearing to need it.

Anne Arundel County also said it was opening warming centers in community rooms at police stations.