From its hottest year to its wettest, to multiple blockbuster snowstorms and one of its most violent thunderstorms in memory, Washington faced an onslaught of extreme weather over the past decade.
Abnormally warm weather happened so often that record-breaking high temperatures turned routine. The cold, meanwhile, was much more muted, but frigid outbreaks of Arctic air still delivered the occasional shock.
And then there was the water. Extreme rain events hit the region repeatedly, once in a while setting off devastating floods.
The frequency of record high temperatures and extreme precipitation was consistent with expectations in a warming world and are a likely signal of what to expect more of in the coming decade.
Below are the 10 most impactful weather events of the past decade in Washington, along with a few notable others that just missed the cut.
10. August and September flooding — 2011
Flooding rain hit the region in late August with Hurricane Irene, and then again Sept. 5-8 from the remnants of Tropical Storm Lee. By the time the flooding waves abated, much of the region had seen more than 20 inches.
Between mid-August and mid-September, at least an inch of rain a day fell on eight days, including four days in a row in early September. The top two days for rainfall were 3.33 inches on Aug. 27 and 2.82 inches on Sept. 7. At the time, August was the 10th-wettest on record since 1871, and September was the fifth wettest. Combined, the 17.76 inches of rain made it the third-wettest August-September on record in the District.
9. Ellicott City floods — July 30, 2016, and May 27, 2018
July 30, 2016, was a day that the District saw little rain: Only 0.33 inches was recorded officially. Less than 30 miles away, however, 6.6 inches were recorded at the Ellicott City station, and it came in a flash.
At the unfortunate confluence of several waterways, devastating flooding ripped through the town’s historic Main Street, leaving two dead and more than two dozen buildings damaged. A number of those buildings were later deemed unfit and torn down. In two hours, 5.92 inches of the total had fallen. With less than 0.1 percent chance of happening in any year, it was classified a 1-in-1,000-year event.
And if that water nightmare wasn’t enough, another hit Ellicott City on May 27, 2018, when six inches of rain deluged the region in less than three hours.
8. Polar Vortex, the second coming — February 2015
During 2014, a star was born. Sure, “polar vortex” could be found in academic papers and scholarly journals before that, but 2014 was when it pivoted into the global consciousness. There was a good reason. The blast of frigid air was intense, even if it was less cold than similar outbreaks in the past, thanks to a warming climate. As impressive as the 2014 blasts from the icy vortex were, February 2015 took it up a notch.
The District finished an astounding 8.7 degrees below normal. The Northeast was one of the coldest places on Earth, compared with normal during the month. It was the coldest February since 1979 in the District. In all the cold, there was a rare record low of 5 degrees on Feb. 20. Additionally, 22 days were below normal, including 10 that were 15 or more degrees below. Some suburbs saw a number of subzero readings, like at Dulles where it hit minus-4 on the morning of the 24th. This was the same month Boston saw record-breaking snow.
7. Commutageddon — Jan. 26, 2011
The storm known as Commutageddon wasn’t a huge one as far as the record books go, and it was generally well-forecast. But it came at a terrible time. The federal government decided to release workers two hours early. All at once, everyone decided to race out of downtown into the heart of an intense, hours-long burst of ice and then snow.
After light snowfall in the morning, temperatures rose above freezing in much of the region. It was a false sense of security. During the afternoon, the main event trucked our way, dropping heavy sleet during thunderstorms before a transition to heavy, wet snow. As roads jammed, snow poured down among continued rumbles of thunder. Thousands of motorists were stranded on roads deep into the night and even into the next morning, while more than 400,000 electric utility customers lost power. All of this from only five inches in Washington, with about four to 10 inches across the region. The event was a sobering reminder that a good forecast cannot overcome bad decisions.
6. The hottest July on record in 2011, and so much more heat
There was so much heat in the 2010s, it’s honestly hard to pick the top event. Because July is the hottest month of the year, the hottest July on record of 84.5 for an average temperature feels as though it fits the bill. Truth is, although we endured the hottest July on record in 2011, 2012 and 2010 registered as the second- and third-hottest.
The District also saw its four hottest meteorological summers during the decade (in order from hottest): 2010, 2011, 2016 and 2012. Rounding out the top seven were 2015 and 2019.
A sample of other heat records during the decade included warmest fall in 2016, warmest February in 2017 and third-warmest winter in 2012. In 2018, we saw the earliest 80-degree reading in a calendar year. This year brought the highest temperature so late in the season when it hit 98 in early October. Plus, low temperatures at or above 80 degrees, once rare events, became mundane. More frequent episodes of significant warmth are a telltale fingerprint of climate change. Expect more in the 2020s.
5. Wettest year on record — 2018
Although it has been soggy before, from mid-July onward in 2018, it often seemed as if it would never stop raining. There were 24 days with at least one inch of rain, topping the old record of 21 days from 1878.
Over the course of the year, 66.28 inches fell, which was almost five more than the old record of 61.33 in 1889. With more than 41 inches of rain from mid-July to the end of the year, 2018 outdid the next closest year (1943) by about 10 inches for the same period.
In addition to Washington’s total, Dulles came in with 66.74 inches, and Baltimore with 71.82 inches. Each state in the region also set an annual rainfall record, including 94.43 inches in Virginia and 84.56 inches in Maryland.
Like the frequent bouts of record-breaking heat, a warming world is showing increased incidents of extreme precipitation over a short period (in July 2019, Washington saw one of its most extreme hourly rain events on record when 3.3 inches fell.). In addition to helping spawn more events like Ellicott City (exacerbated by terrain), it means it may not be long until we test these records again.
4. Hurricane Sandy — Oct. 29, 2012
Hurricane Sandy was the superstorm the Northeast long feared. A hurricane turned “frankenstorm,” thanks to its merger with a cold front sweeping in from the north, it launched northward from the Caribbean before slingshotting into the East Coast. Despite making landfall north of Washington, near Atlantic City, the federal government in the District was closed for two days, and public transit was also halted. An extreme rarity for something other than snow.
While the brunt of the storm hit New Jersey and New York City, Sandy unleashed almost five inches of rain. It also set all sorts of records across the Northeast, including a second-lowest pressure on record north of North Carolina, with a landfall of 946 millibars in New Jersey. In the Washington area, it might have been slightly more bark than bite, but it was enough to bring down lots of trees and cause at least half a million outages in the region.
3. Snowzilla — Jan. 22-23, 2016
The January 2016 blizzard named “Snowzilla” ranked as one of Washington’s all-time great winter storms. With 17.8 inches of snow on the ground at Reagan National Airport, the storm is tied as the District’s fourth-greatest snow event on record. It might have ranked higher but for a measuring controversy.
The storm dropped one to three feet of snow across the area from southeast to northwest, including the record in Baltimore (measured at BWI) with 29.2 inches. Occurring just six years after the blockbuster snows during the 2009-2010 winter, it raised the question of whether such monumental winter storms are increasing in a warming world.
2. The derecho — June 29, 2012
Derechos, violent summertime thunderstorm complexes that move ahead at breakneck speeds, are somewhat uncommon in the Washington region. Translating to “straight ahead” in Spanish, even the name sounds ominous, and the 2012 version certainly delivered a huge blow to the region.
The day of the derecho started sultry and turned ungodly hot. The high temperature of 104 degrees was the hottest on record for the month of June. Often when it’s that hot, there’s high pressure squashing storms. Not this time. The bowing complex of storms grew as it raged and raced across the Ohio Valley.
With the storms due to arrive late in the evening, the main question in our area was: Would the derecho survive the trek across the Appalachian Mountains? The exceptional heat and humidity, fuel for the thunderstorms, helped ensure it did, and in an unforgettable way. Most locations in the region saw wind damage as widespread gusts of 60 to 80 mph blasted the area, and for longer than your typical storm. Thousands of trees came down, and half a million customers lost power in the D.C. area in the middle of one of the most punishing heat waves on record.
1. Snowmageddon — Feb. 5-6 (Jan. 30 through Feb. 10), 2010
The first decade of the new millennium closed with Washington’s biggest December snowstorm on record, when the “Snowpocalypse” hit (Dec. 17 to 19, 2009). But the new decade launched with an even more extreme onslaught of snow. Between Jan. 30 and Feb. 10, an unfathomable 38.3 inches of snow fell in Washington, the most snow on record in such a short time.
The biggest snow event of this stretch, dubbed Snowmageddon, on Feb. 5 and 6, tied with Snowzilla as the fourth-biggest on record. At Dulles, Snowmageddon was the biggest snowstorm on record with 32.4 inches. Just three days after Snowmageddon, a follow-on blizzard on Feb. 9-10, dubbed “Snoverkill,” unloaded another 8 to 20 inches of snow on the region. For the whole 12-day stretch, some of our northern suburbs saw as much as 40 to 60 inches. Then, in true Washington style, snow ended, and spring set in early. The coming summer was the hottest on record.
So not to stack the list with snowstorms, a few events like the St. Patrick’s Day snowstorm (2014) and Snochi (2014) were excluded but were contenders for this list. Let us know in the comment area if you think we missed anything important.
Jason Samenow contributed to this report.