With the return of some warm air, precipitation averages begin go back up, but March can also be quite dry. The battle between growing warmth to the south and remnant winter cold to the north can spawn intense low-pressure systems, and the area can sometimes be pasted by a heavy wet snowfall.
Keep reading for more in this 12th installment of a year-long series of posts detailing specific statistics on climate norms, extremes, and averages for the each month in Washington, D.C…
Average* March precipitation is 3.48”, and that’s up about 1” from February, in part due to the additional moisture that comes with incoming warmth and in part because March storms may “cut off” from the flow and bring rain for longer periods of time. The change from the last climate normal set running 1971-2000 is a net loss of 0.12”.
It has rained as much as 2.79” on the 9th in 1881. But, while precipitation averages are on their way back up, March has only seen six days with 2” or more rainfall, which is still low compared to the months that follow.
The wettest two Marches exceeded 8” of rain. The wettest March, in 1981, finished with 8.84” of rain. On the dry end, a measly 0.05” of rain fell just a few years ago in March 2006.
Normal March snowfall in D.C. is 1.3”, this is down 0.4” since the last 30-year climate average. In recent years (back through the 2000s), March snow has been hit-or-miss. It occurs about every other year on average with most instances quite low as far as accumulation goes.
About 150 accumulating snow events, including those which were primarily rain but had some snow stick, have occurred in March since records began in the late 1880s. 33 percent of those events reached accumulation of at least 3”. As recently as March 2009, an event dropped 5.5” of snow on the first days of the month.
March is a month of warming but variable temperatures and plenty of wind as the patterns shift around. The average monthly temperature of 46.8 rose 0.3 degrees from the old climate normal to the new one.
The warmest March D.C. has seen was 56.2 degrees for an average temperature, and it happened in 1945. It’s been as cold as 34.5 degrees (colder than our current average for January) way back in 1885, and as low as 35.6 as recently as 1960.
The month starts off with an average high of 51 degrees with a low of 34 degrees, and as it closes the average high has risen to 61 degrees with a low of 42 degrees. While days can be chilly, particularly when clouds and precipitation block out the increasingly strong sun, the chances of getting a freeze in D.C. dwindle quite a bit through the month.
Examining the 1980-2010 climate period, high temperatures in the 50s are most common for March and happen about 32 percent of the time. 40s and 60s make up about 25 percent each with 70s the next most likely at 10 percent, and other values rounding out the final percentages. Lows in the 30s still dominate with about 46 percent of days having lows in that range. 40s made up 32 percent of lows, with 20s 13 percent and 50s 7 percent. Other ranges made up the last few sets of days.
The warmest high for the month is 93 degrees, and that happened on the 23rd in 1907. All three March 90-degree days happened in late March 1907. The warmest it has been at National Airport is 89 degrees on the 12th in 1990. It’s been as cold as 20 degrees for a high in both 1873 and 1885. As recently as the first in 1980, the high was as low as 21 degrees.
The lowest March temperature has been as cold as 4 degrees way back in 1873 on the 4th. At National, the chilliest it has been in March is 14 degrees on several occasions, and as recently as the 3rd in 2009. The warmest low temperature was a balmy 66 degrees on the 25th in 1913, and again on the 22nd in 1948.
30-year (1981-2010) Averages / Overall (all history) Averages...
Highs below 50: 9.5 / 11.8
Highs 60 or above: 11.5 / 9.8
Highs 70 or above: 4.1 / 3.3
Highs 80 or above: 0.8 / 0.7
Lows 32 or less: 8.0 / 10.8
Lows 40 or above: 12.4 / 9.7
Days with at least a trace of rain: 14.8 / 15.6
Days with .1” of rain or more: 6.5 / 7.1
Days with .5” of rain or more: 2.4 / 2.4
Days with 1” of rain or more: 0.9 / 0.8
Days with at least a trace of snow: 3.3 / 4.2
Days with 1” of snow or more: 0.4 / 0.9
Days with thunder: 1.2 / N/A
Days with hail: 0.0 / N/A
-This count is done through records on Weather Underground, and does not include the entire historical period.
All-Time Records (High / Low)...
Highs below 50: 25 (1960) / 1 (1977)
Highs 60 or above: 22 (1946) / 0 (1958)
Highs 70 or above: 16 (1945) / 0 (18 years)
Highs 80 or above: 9 (1945) / 0 (95 years)
Lows 32 or less: 24 (1960) / 0 (2010)
Lows 40 or above: 21 (2000) / 0 (1900, 1905)
Days with at least a trace of rain: 23 (1936) / 8 (1873, 1915)
Days with .1” of rain or more: 12 (1892, 1948, 1994) / 0 (2006)
Days with .5” of rain or more: 6 (6 years) / 0 (11 years)
Days with 1” of rain or more: 4 (1891, 1903, 1924) / 0 (69 years)
Days with at least a trace of snow: 11 (1958, 1960) / 0 (6 years)
Days with 1” of snow or more: 5 (1906) / 0 (67 years)
Days with thunder: 4 (2000) / 0 (11 years)
-Same as above. (30-year high / low listed)
Daily climate records for Washington, D.C., 1871-present
- See selected and additional statistics compiled for this post (Excel)
*All averages or normals, unless otherwise noted, refer to the 30-year period of 1981-2010. Unlike initial months in this series, a full set of new climate norms is now available and will be used throughout. Past months will be edited to reflect the new norms.
While numerous local climatology statistics including daily, monthly, and seasonal normals and records are available from National Weather Service Baltimore/Washington, there are myriad other pieces of information which help frame the story. Rather than attempt to recreate what is already available, this series of posts will act as a companion to most information presented there.
This is the twelth installment of a series of living documents. Through early 2012, each month will be broken down in a similar or evolving way. As input is taken from the community, some items may be added to or changed in older postings. These postings will be updated as necessary to reflect changes when needed. Other articles may also become part of this series.
Feel free to share thoughts or additional data you may be interested in seeing.
Learn more about each month:
-April weather in Washington, D.C.
-May weather in Washington, D.C.
-June weather in Washington, D.C.
-July weather in Washington, D.C.
-August weather in Washington, D.C.
-September weather in Washington, D.C.
-October weather in Washington, D.C.
-November weather in Washington, D.C.
-December weather in Washington, D.C.
-January weather in Washington, D.C.
-February weather in Washington, D.C.
-March weather in Washington, D.C. (viewing)
Article last updated: March 12, 2012.