When thinking of snowy places in the United States, D.C. doesn’t typically come to mind. But it certainly gets its fair share of snow, in some years at least.
To serve as a guide, we’ve compiled a collection of D.C. snow statistics and briefly detail them below.
Let’s get snowin’…
If you like snow, perhaps the most important questions are: When will the first flakes fall? And how long does the snow season last into spring?
Don’t expect much before the New Year
Throughout the modern weather record, dating to the 1880s, the District’s first measurable (0.1 inches or more snow) event has tended to come along in early-to-mid December. Flakes often fly in November without amounting to much in the city.
The first inch has typically come by the latter part of December, somewhere around Christmas in the long-term sample, but probably later in recent decades as our season has compressed thanks to warming temperatures over time.
A two-inch event might be expected by early January, then perhaps a four-inch event around mid-January. Using the averages as a window of sorts, then the city’s best timeframe for snow (if you’re a snow lover) is from roughly mid-January to mid-February.
Snow hopes tend to quickly dwindle by late February, but our typical last measurable snow event often waits until March. As recent history has shown, March can be a wintry month under the right conditions. April, like November, is quite unlikely to deliver even though it has in the past.
January and February bring the snow
As the bounds for first and last snowfalls above tell us, D.C. snow is largely a January and February ordeal.
The official D.C. average, based on averages spanning 1981-2010, is 15.4 inches. About 75 percent of the city’s snow tends to fall January through February, with over 60 percent of the cumulative total in that same range. Although February is a shorter month, it averages slightly more snow than January as the first signs of springtime moisture mix with well-aged cold air.
The present average is likely somewhat misleading as it includes an event like the very unlikely Veterans Day snowstorm of 1987, one of the most anomalous winter events the region has seen, and the outlier Snowmageddon winter of 2009-2010 (56.1 inches). A median snowfall might offer a clearer picture thanks to D.C.’s perplexing mix of lots of small storms with some huge ones. The 1981-2010 median snowfall is 11.7 inches, arguably a more realistic characterization of what is normal.
Early and late season events
A full seven months of the calendar year have witnessed accumulating snow in D.C.
The earliest measurable snow on record was a small event on October 9-10, 1979. October also claims the earliest inch, with one event in 1940. The aforementioned Veterans Day storm claims the title for the earliest major event, and a storm in December 1932 is the earliest Washington has ever seen a foot or more.
In winter’s waning days, March has produced some memorable snow events, including two of the top 25 on record. A big late-March storm in 1942 dumped 11.5 inches on the city and it is the latest major snow storm on record.
April snow? April Fools’ you might think, except not on April 1, 1924 when 5.5 inches fell. The latest inch, actually three of them, came on April 11-12 in 1918. The latest measurable event came on April 28 in 1898. April snow is hard to come by these days, though.
Big D.C. snowstorms
All top 25 snowstorms for the District since records began have been greater than 10 inches. They range from 28.0 inches on the high side to 10.7 inches on the low.
The infamous Knickerbocker snowstorm of January 1922 is the record holder for the District at 28 inches. It’s believed to have been about the same intensity as Snowmageddon in 2010, or Snowzilla in 2016. The main difference was likely the placement of the heaviest snow.
The Great Blizzard of 1899 — ranked number two, which also delivered D.C. its all-time lowest temperature of -15F — is the only other storm on record to drop 20 inches or more with a 20.5 inch total.
Presidents’ Day 1979 (number three with 18.7 inches), Snowmageddon 2010 plus Snowzilla 2016 (tied number four at 17.8 inches), and the Blizzard of 1996 (number five with 17.1 inches) round out the top five in the city.
Interestingly, of the top 10 D.C. snowstorms, all but three occurred after 1950.
Small snow events
While big storms are what snow lovers hunt, it’s the littler ones that make up much of our winter snow tallies. An eight inch snowstorm only comes along about one in every fifteen events.
A full 40 percent of the city’s snow events haven’t even managed one inch of snow. Storms such as those range from cold clippers that are starved of moisture and drop a half inch of fine powder to events that start briefly as snow but turn over to rain. One thing they generally have in common is they don’t bring life to a halt.
Small but more consequential one to two inch events fill a pretty sizable chunk as well, making up almost another 25 percent of events. Expanding the range further to span the barely measurable events depositing 0.1 inches to those just shy of winter storm warning criteria at 4.9 inches, we find over 85 percent of D.C. snow events.
Minor to moderate snow events are most typical in D.C., even if dreams of blockbusters dance in our heads.
Now that the basic snow stats are in mind, let’s take it up one more level of nerdiness. Get ready to wow your friends next time it snows.
Heavy snow days
Ranging from events unloading 9.1 to 21 inches in 24 hours, there have been plenty of very snowy days in D.C.
On ten days since the late 1880s, District residents have witnessed a foot or more of snow fall in the city. The Knickerbocker snowstorm tops the charts again just as it does with full-event totals above. Three-quarters of Knickerbocker’s total snowfall came on January 28 alone.
More recently, D.C. has seen a foot or more snow in one calendar day in January 1996 (16.4 inches), February 2003 (13.3 inches), and December 2009 (15.0 inches). Other big time storms, like Snowmageddon, dispersed their snow blanket across midnight hours, so they don’t all rank as highly on a single-day basis.
Snowy days can become snowy months
The snowiest months in D.C. have deposited a range from over a foot and a half to close to three feet. January, February, and March, unsurprisingly, comprise the snowiest months. December is often too early for big snow, though December 2009, and its record-setting “Snowpocalyspe” storm, just missed the list.
January 1918 was perhaps the most unique among snowy months in that it had eight(!) separate snow accumulation events. Three were six inches or greater, with the rest in a general 0.5 to 2 inches zone. Many other months are heavily dominated by one large event.
For quick reference — and likely the topic of a future post in itself — a typical full winter has about seven accumulating snow events, three to four of which are one inch or greater. January 1918 was truly special with that perspective in mind!
Since they aren’t all captured above, snowfall records by month are as follows: October (1925), 2.2 inches; November (1987), 11.5 inches; December (2009), 16.6”; February (1899), 35.2 inches; March (1914), 19.3 inches, April (1924), 5.5 inches.
Just like snowy days can turn into snowy months, snowy months build up snowy winters. There have been some doozies.
Historical winter snow totals
The top 15 snowiest winters range from 36 inches at the low end to 56.1 inches at the top. Of course, many local residents remember the leader for snowiest winter on record, given it was just a few years ago in 2009-2010.
Meager snow is the other side of the D.C. winter roulette wheel.
Two winters came in with a pathetic 0.1 inches for the record low, most recently during the 1997-1998 El Nino. The 15th least snowy winter only managed 5 inches.
Two of the top 10 least snowy winters have been in the last five years, with a two-winter snow drought that included 2012-2013’s sad two inches of snow (third least snowy on record). Ouch!
All this snow can lead to some big snow depths, i.e. the amount of snow measured on the ground at a specific time.
Deep D.C. powder
While Washington isn’t a snow town, it could certainly be confused for one at times. Anyone here in 2010 knows that. It felt like Alaska for at least a few brief moments.
Looking at peak snow depth registered during snowy years, we find 1899 in the lead with an astonishing 34 inches — that’s almost three feet downtown!
In the 1.5 foot or more zone, there are well-remembered dates in January 1987 (18 inches), January 1996 (20 inches), February 2010 (21 inches), February 1979 (22 inches), and January 1922 (26 inches).
It’s at least somewhat true that one large snowstorm can make or break a winter in the area, especially in D.C.
Duration of snow on the ground
A few winters feature periods where snowstorms keep on coming. Some winters, cold air is plentiful enough to allow snow to persist on the ground without refreshment.
Washington’s lengthiest stretches of snow cover — defined here as days with at least one inch of snow on the ground — are all more than two weeks long. Leading the pack is a nearly month-long period in 1961 that ran from January 20 through February 17.
In 1961’s case, it was due to a quick succession of moderately-sized snowstorms that started January 19 and lasted until February 12. There were five separate snowstorms, all of which dropped three inches or more.
Similar durations also occurred in 1895 and 1905, the other top-placers with 27 days of snow cover.
In preparing to close the book on important D.C. snow stats, one we can’t pass up is the El Nino and La Nina connection.
The equator is far away but it matters
The oceanic and atmospheric phenomenon known as El Nino Southern Oscillation (ENSO), and its phases of El Nino or La Nina conditions often play a significant role in weather across the region during winter.
Since the city and surroundings are often living on the edge between rain and snow, a specific ENSO phase is not necessarily a sure bet for more or less. The region generally gets more snow compared to average in El Nino winters, although the two least snowy winters on record were also El Ninos. La Nina more generally tends to limit upside snowfall risk around here, but the epic winter of 1995-1996 featured a weak La Nina.
Almost there. Thanks for making it this far! Let’s end on a heavy (so much snow!) note.
Way past our ears in snow
If snow lovers could devise a way to never let snow melt, the landscape would certainly look quite different. Adding up all the snow that’s fallen in the city since the snow records began the 1880s, many iconic monuments would be frozen within what we can call the District Glacier.
The 200 feet of snow that has fallen would top the White House by a good dozen stories. The beautiful white dome of the Capitol just peeks out above the snow depth. And the Washington Monument would stand as a beacon, a reminder of days before the District Glacier took over.
Posted on January 12, 2016. Last updated on January 24, 2016.
