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Posted at 11:40 AM ET, 02/14/2012

What is Washington, D.C.’s weather like in February? Breaking down norms and extremes


February 6, 2010 — Snowfall frames the U.S. Capitol at the tail end of Snowmageddon, Washington’s 3rd largest February snowstorm. Photo by author.
February, the final month of meteorological winter (Dec-Feb), features plenty of cold air many years, but also a hint of what’s to come in the months ahead with a hint of milder times. The monthly average temperature climbs back up into the upper 30s, and by the end of the month average lows climb above freezing with highs into the 50s.

On average, precipitation remains at a cold-season nadir. We can mainly blame that on the cold temperatures still not being able to hold much moisture, plus the fact that the juiciest jet streams are often displaced well to the south. Still, the month has provided many memorable snowstorms, including several in recent decades.

Keep reading for more in this 11th 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…

PRECIPITATION

Average* February precipitation is 2.62”, which is the lowest of any calendar month, but in reality is very similar to January when you consider that February has 28 days (most years!). Together, Jan-Feb represent the “valley” of D.C. precipitation trends, though August also falls below 3”on average. The change in February precipitation norms from the old 1971-2000 average to latest 1981-2010 average is only 0.01” less.


Monthly rainfall (in inches) by year in Washington, D.C. from 1871-2011. See sources for data.

The most rain that has fallen on one day is the 2.29” on the 6th in 1896. The 22nd in 2003 is a close runner up at 2.27”. There have been five days with more than 2” of precipitation. This is up one from January, which features the least “2-inch days” of any month of the year, and the frequency of such days will continue to increase into the warm months.

The wettest February on record, 6.98” of liquid equivalent, came during the 2002-2003 El Nino season that produced prolific snowfall up and down the East Coast, including a winter snow total of 40.4” in D.C. Just a few years later, the driest February on record came along in 2009 when only 0.35” of precipitation fell.


Monthly snowfall (in inches) by year in Washington, D.C. from 1888-2011. See sources for data.

Normal snow for February is 4.8”, which is less than January’s total of 5.6”, but we should again acknowledge that February is typically three days shorter than January. In reality, these monthly totals are nearly equal by day and February edges out January slightly (through 2011) historically. However, the 4.8” is down 0.4” from the 1971-2000 climate period.

A little more than 250 events -- or over 25 percent of the cold-season total -- with snow accumulation greater than 0.1” (including storms which were mainly rain) have occurred in February. Moving to the 5” threshold, thus removing a lot of rainstorms, we see about 30% of our 5”+ snows during February. That’s roughly equal to January, and again considering the shorter month, perhaps an indication February is a month to look for winter storm warnings.


The top 10 accumulation events in February at Washington, D.C. Numbers are in inches of snowfall.

The biggest February snowstorm on record is the Blizzard of 1899. This storm dropped 20.5 frigid inches of snow on Washington. Temperatures were in the single digits in the morning and about 10 degrees during the day throughout the two main days of this event, and it started late on the day that’s the coldest on record in D.C. The storm also helped February 1899 earn the status of snowiest month on record at 35.2”. February 2010 threatened it, but did not make it there despite 2009-10 surpassing 1898-99 as the snowiest winter on record.

The most snow that’s fallen on one day is the 16.4” which accumulated on the 11th in 1983. Six single days have seen a foot or more of snow during February. There has never been more than the 34” measured on the ground during the morning of February 14 and 15 1899, following the Blizzard of 1899. For perspective, there was 21” of snow on the ground at peak snow cover (Feb. 11) during winter 2009-2010.

TEMPERATURES

February is characterized by still chilly but rising temperatures. The monthly average of 39.0 degrees is colder than December, but three degrees milder than January. As with every other month, the average temperature in January increased during the 1981-2010 climate period when compared to that of 1971-2000. February is now 0.9 degrees warmer than it used to be.


February temperature averages throughout recorded history (in degrees F) at Washington, D.C. Red line is normal for the month. See sources for data.

The February average temperature has been as warm as 46.9 degrees in 1976, which is actually lower than January’s record warm month, even if still quite mild! On the other side of the spectrum, it’s been as cold as 24.6 degrees for the monthly average back in 1934. More recently, the coldest February at National Airport was the 28.4 degrees in 1979.

Daily averages start at 44 degrees for a high temperature and 29 degrees for a low. They rise to 51 degrees for a high and 33 degrees for a low by month’s end. The 24th is when Washington sees its average low rise above freezing while heading out of the cold season, where it won’t return until mid-December. As February closes, high temperature averages increase a degree about every three days.


Raw (non smoothed) odds of a low temperature 32 degrees (freezing) or below at Washington, D.C., by day of the month. Both long-term and recent trends exhibit a similar pattern overall. See sources for data.

When examining the 1981-2010 climate period and using it as a guide, we get an idea of what D.C. can expect for highs and lows during February. 40s and 50s make up a majority of the daytime highs, at 35 percent and 25 percent respectively. Highs in the 30s represent 22 percent of days, highs in the 60s make up 12 percent, with 20s, 70s and teens rounding out the final six percent. When it comes to lows, 43 percent fell in the 30s, 35 percent in the 20s, 13 percent in the 40s, and 8 percent in the teens. 50s and 0s comprised the final 1 percent.

Unlike the other meteorological winter months of December and January, February has witnessed temperatures in the 80s. The highest temperature ever in the month was 84 degrees on the 25th in 1930, and the other occurrence was an 82 degree day in 1948. When it comes to coldest highs, the 10th in 1899 saw one of only 4 degrees! The coldest daytime high at National Airport is the 13 degree high on the 17th in 1958.

The coldest reading all time (February or otherwise) occurred on Feb. 11, 1899 when the thermometer dipped to -15 degrees! The 26 coldest February temperatures, including 10 of them below zero, all occurred prior to the move of D.C.’s official observing station to National, where the coldest morning low in February is 4 degrees on the 2nd in 1961. There are also, every now and then, balmy mornings in February. In 1891 the coolest it got on the 17th was 61 degrees and at National there’s been a low as warm as 59 in 1976, also on the 17th.

DATA

30-year (1981-2010) Averages / Overall (all history) Averages...

Highs below 50: 17.2 / 19.2
Highs below 40: 7.3 / 8.9
Highs 32 or less: 1.9 / 3.2
Highs 60 or above: 4.0 / 3.1
Lows below 40: 24.3 / 25.4
Lows 32 or less: 16.9 / 18.7
Days with at least a trace of rain: 12.8 / 13.2
Days with .1” of rain or more: 5.4 / 5.9
Days with .5” of rain or more: 1.7 / 2.0
Days with 1” of rain or more: 0.3 / 0.5

Days with at least a trace of snow: 5.4 / 5.9
Days with 1” of snow or more: 1.3 / 1.6

Days with thunder: 0.4 / NA
Days with hail: 0.0 / NA
-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: 28 (1905) / 8 (1976)
Highs below 40: 22 (1905, 1934) / 0 (1952, 1998, 2002)
Highs 32 or less: 13 (1904) / 0 (30 years)
Highs 60 or above: 14 (1976) / 0 (26 years)
Lows below 40: 29 (4 years) / 17 (1981)
Lows 32 or less: 28 (1901) / 7 (1998)
Days with at least a trace of rain: 21 (1950) / 4 (1877, 1901)
Days with .1” of rain or more: 13 (1899) / 1 (1977, 2009)
Days with .5” of rain or more: 6 (1883) / 0 (19 years)
Days with 1” of rain or more: 3 (1971, 1979) / 0 (89 years)

Days with at least a trace of snow: 14 (1905) / 0 (1977
Days with 1” of snow or more: 8 (1899) / 0 (35 years)

Days with thunder: 2 (1999) / 0 (20 years)
-Same as above. (30-year high / low listed)

SOURCES

Daily climate records for Washington, D.C., 1871-present
- See selected and additional statistics compiled for this post (Excel)

D.C. climate norms 1981-2010

D.C. February daily norms and records

D.C. monthly temperatures

D.C. monthly precipitation

NWS Baltimore/Washington climate information

NOTES

*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.

ABOUT THIS SERIES

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 eleventh 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. (viewing)

Article last updated: February 14, 2012.

By  |  11:40 AM ET, 02/14/2012

Categories:  Local Climate, Latest

 
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