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Evan Horowitz

How cold are Boston winters?

A pedestrian bundled up against winter walked along Van Ness Street outside of Fenway Park.
A pedestrian bundled up against winter walked along Van Ness Street outside of Fenway Park.Jim Davis/Globe Staff

If you’ve dared to face the outdoors recently, you’ve seen steam rising from every breath and faces hidden away behind hats and scarves. Yesterday’s high was a bitter 18 degrees, and if the forecast holds, temperatures in Boston may not break freezing for several days.

Cold weather is hardly a novelty in Boston, but such periods of deep freeze are mercifully rare. Most winters, there are only a handful of days below 20 degrees. It’s actually more common to see days in the 50s than days in the teens.

How often is it this cold?

Only rarely does the high temperature in Boston stay below 20 degrees. In a terrible winter, there might be eight or nine days below 20 degrees, but most years it’s more like three days.

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Temperatures below freezing are far more common. Generally speaking, one in every four days from December through February is below freezing — still cold, but not quite so numbing. Last year was an especially bad winter by this measure, with 38 thawless days.

The first month of the year in Boston has historically been the coldest with the lowest average temperature and highest snowfall average. According to the City of Boston, January’s average temperature is 28.8 degrees and the average is a foot of snow.

Monthly temperature and snow averages in Boston
January sees the most snow and coldest chills
Month Average Temperature (F.) Snowfall Average (in.)
January 28.8 12
February 29.4 11.3
March 37.1 7.9
April 47.2 0.9
May 57.9 0
June 67.2 0
July 72.7 0
August 71 0
September 64.1 0
October 54 0
November 43.7 1.3
December 32.8 7.5
DATA: City of Boston
Globe Staff

How does Boston compare to other cities?

As cold as last winter was here in Boston, it was practically spring-like compared to some other North American cities. People in Chicago suffered through 18 days of sub-20 degree temperatures. Minneapolis saw more than 50 days.

Has Boston been getting warmer over time?

This year, so far, has been warmer than 2014 — which had the lowest average temperature since 2009, according to data from Weather Underground. But the wind chill is making this year’s warmer weather feel colder. So far this month the wind speed average has been 13 miles per hour — which is the fastest it’s been since 2004.

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January temperatures in Boston since 2005
Average temps for the first month of the year and lowest recorded daily temp
Year Average Temp (F.) Lowest Temp (F.)
2015 31.33 15
2014 27.68 2
2013 31.77 4
2012 34.45 6
2011 27.81 -2
2010 29.81 6
2009 25.13 6
2008 33.65 7
2007 33.03 3
2006 36.68 10
2005 26.48 -2
DATA: Weather Underground
Globe Staff

Despite recent relative warmth, there’s no obvious trend in these numbers. Looking at Boston’s January temperature since 1920 shows simply that some years are colder and some are warmer.

Wind speed, which can make the temperature feel colder, doesn’t show an obvious trend either.

One thing about global warming is that it’s expected to produce more unpredictable and extreme weather patterns, which could mean that in the future we’ll see bigger swings between bitter cold and balmy highs.


Evan Horowitz digs through data to find information that illuminates the policy issues facing Massachusetts and the United States. He can be reached at evan.horowitz@globe.com. Follow him on Twitter @GlobeHorowitz