Tuesday morning was Baltimore's coldest for the month of March since record-keeping began in the 1870s, with a low of 4 degrees reported at Baltimore-Washington International Thurgood Marshall Airport by 6 a.m.

The National Weather Service confirmed the record later Tuesday morning. The reading at the airport, Baltimore's point of record since 1950, was 1 degree lower than a record low for Tuesday's date and for the entire month, 5 degrees set on March 4, 1873 at the U.S. Customs House downtown. The old record was set on the day of President Ulysses S. Grant's second inauguration.

The last time Baltimore recorded single-digit temperatures in March was March 4, 2009, and Tuesday was only the sixth such occurrence on record, according to the weather service. It was also the latest occurrence of temperatures below 5 degrees in Baltimore, officials said; the previous record was Feb. 24, set in 1889.

Dulles International Airport in Northern Virginia also tied its record for coldest March temperature, hitting 1 degree below zero. 

The historic freeze was expected to complicate snow cleanup efforts. By Monday evening, Anne Arundel County schools had canceled classes Tuesday and Baltimore City and Baltimore and Harford counties planned to start two hours late. Carroll and Howard counties had been set for delays but closed schools by early Tuesday morning.

Clouds were forecast to increase by midday, with temperatures expected to peak in the upper 20s. Temperatures rose quickly after sunrise, reaching 18 degrees by 9 a.m. in part thanks to sunshine that is intensifying in strength as spring nears.

Lows early Wednesday were expected in the low- to mid-teens, with highs in the mid-30s under partly to mostly cloudy skies in the afternoon. A bit of a warm-up had been expected Thursday and Friday, but temperature forecasts have dipped, with highs expected in the upper 30s and mid-40s, respectively.

Thursday night could bring another chance for snow, with overnight lows in the upper 20s.

The weekend could bring temperatures back up to around normal for this time of year, with highs around 50 degrees.

But local meteorologist "Eric the Red" suggests against getting used to any sort of warm-up, with more wintry weather in the 10-day forecast.

"Sorry to be the harbinger of bad news... but the extended range forecasts aren't pleasant," he wrote in an e-mail. "At all.  Like, it may not be too late to go buy a snow blower."