A blast of Arctic air has made its way into Maryland, bringing lows in the single digits across Central Maryland.
Temperatures fell to 6 degrees early Thursday morning at Baltimore-Washington International Thurgood Marshall Airport, and a 6 mph breeze made it feel like 5 degrees below zero. That was 2 degrees away from matching a record for Thursday’s date set in 1965 and tied in 1966.
Overnight, with 10 mph winds, and 20 mph gusts, wind chills were forecast as low as 10 degrees below zero around Baltimore and 20 degrees below zero to the north and west, along the Mason-Dixon Line.
A wind chill advisory in the Baltimore region expired at 10 a.m. Thursday, but remained in effect until noon in Carroll and Harford counties, northern Baltimore County and northwestern Howard County.
The advisory means that cold air and the wind will combine to create dangerously low wind chills. Frostbite and hypothermia can occur if precautions are not taken.
High temperatures are forecast only in the upper teens or lower 20s Thursday afternoon, with gusts up to 25 mph making it feel like the single digits throughout the day.
On Wednesday evening, when an Arctic front moved through, bringing a burst of snow with it, temperatures fell 10 degrees within an hour, to 24 degrees at the airport. BWI temperatures fell to 16 degrees by 6 p.m.
The cold is not forecast to let up much, if at all, on Friday. Lows in the lower teens and highs in the upper 20s are forecast. Calmer winds are expected — and more snow showers are again possible.
Interim Baltimore City Health Commissioner Mary Beth Haller declared a “Code Blue” emergency from Tuesday night through Friday morning, calling the temperatures “dangerously cold.” The designation prompts agencies to offer free meals for senior citizens, encourage homeless people to seek shelter and help residents apply for utility bill assistance.
Maryland health officials encouraged residents to dress properly if going outside, recommending multiple layers, including a windproof and water-resistant outer layer, a hat and gloves.
They also urged people to keep fireplaces and wood-burning stoves clean, to provide plenty of space around heaters of any kind, and to never leave them unattended.
Baltimore public works officials said they are preparing for the likelihood of water-main breaks, and urged residents to protect outdoor or exposed pipes from the cold. They encourage shutting off water to outside faucets and allowing a trickle of water to flow from a basement faucet, because moving water is less likely to freeze.
January 2019 temperature swings
The Baltimore City Department of Public Works is canceling street sweeping for the remainder of the week. Parking restrictions for street cleaning will not be enforced.The machines put down a spray of water to control dust as they sweep. In extreme cold, the street sweeping equipment can freeze and become damaged.
The chill is coming from a piece of the polar vortex, an area of frigid air and low atmospheric pressure over the North Pole (there’s another one over the South Pole) that is normally confined to that region. But when a surge of warmer air pushed its way over the North Pole last month, it caused the polar vortex to split, sending pieces of it intruding into parts of Europe, Siberia and now the United States.
The Plains and Great Lakes states got the first taste of the polar vortex Tuesday, when temperatures fell as low as 27 degrees below zero in the Dakotas and Minnesota. Wind chills were as cold as minus 59. And it was advancing eastward.
Wisconsin, Illinois and Michigan were under states of emergency as the cold moved in Wednesday. The U.S. Postal Service took the rare step of suspending mail delivery across much of the region. More than 1,600 flights were canceled at Chicago’s airports Wednesday, including more than 1,300 at O’Hare International Airport, one of the nation’s largest airports.
Temperatures in parts of the Midwest were lower Wednesday than in Antarctica, where the Amundsen-Scott South Pole Station hit negative 25 degrees — compared to Fargo, North Dakota’s negative 31 degrees and Minneapolis’ negative 27 degrees, according to the National Weather Service.
In Chicago, temperatures plunged early Wednesday to minus 23 degrees, breaking the day’s previous record low set in 1966 — and colder than the weather in Barrow, Alaska, the most northern town in the U.S. By 2 p.m. central time, they had warmed to 16 below zero. If the high temperature fails to reach 14 degrees below zero, it would break a record set on Jan. 18, 1994.
And that doesn’t include wind chill, which in northern Illinois made the air feel as cold as negative 57 degrees. The weather service warned that a wind chill of minus 25 can freeze skin within 15 minutes.
“These are actually a public health risk and you need to treat it appropriately and with that effort,” Chicago Mayor Rahm Emanuel said. “They are life-threatening conditions and temperatures.”
Scientists said the unusually cold weather doesn’t disprove global warming, as President Donald Trump suggested in a tweet Tuesday. While the eastern U.S. freezes, average temperatures worldwide on Tuesday were 0.54 of a degree warmer than the 1979 to 2000 average and 1.6 degrees warmer than it was on average about 100 years ago, according to data from the University of Maine’s Climate Reanalyzer and NASA.
Australia was meanwhile broiling under triple-digit heat. Adelaide last week hit 115.9 degrees, setting the record for the highest temperature ever recorded in a major Australian city.
The Associated Press contributed to this article.