Temperatures plummeted to 6 degrees at Baltimore’s point of record early Thursday morning — frigid, for sure, but still almost 15 degrees away from the region's historically coldest weather.

The coldest temperature ever recorded in Baltimore is 7 degrees below zero. The region has hit that mark on five occasions, most recently in 1984.


And it hasn’t come all that close since.

The last time temperatures dropped below zero at Baltimore-Washington International Thurgood Marshall Airport, the point of record, came in 1996. That was the 32nd time temperatures dipped below zero in Baltimore’s record book, and at that point, chances were about one in four that it would get that cold in any given year.

But since then, the coldest reading at BWI has been 1 degree on three occasions, the most recent being Jan. 7, 2018.

What is the polar vortex? It's not a new weather phenomenon — it's an area of frigid air and low atmospheric pressure over each of Earth's poles. But it is making an unusual intrusion into the eastern United States, actually the result of warming at the North Pole.

Single-digit lows remain common, though, occurring in each of the past five years and 16 years in the past two decades. On average, the coldest temperature in Baltimore during any given year is about 6 degrees — the same as Thursday’s low.

And single-digit cold has become more frequent in recent years. On average, temperatures drop into the single digits about three times each year. Last year, it occurred four times, and in 2015, 10 times.

In 2014, it got that cold on 12 days — matching a record dating to 1912.

Thursday morning was the first time in 2019 that BWI temperatures dropped into the single digits, but the chill waned Friday heading into the weekend with a high of 50 forecast for Sunday.