DCist is providing special coverage to climate issues this week as part of Covering Climate Now, a global collaboration of 250 news outlets designed to strengthen coverage of the climate story. In addition to publishing new work, we are also resurfacing past stories.
If you haven’t noticed yet, the summer of 2019 has been a hot one.
Things got off to a toasty start when Earth recorded its hottest ever June last month. Then, Paris shattered its all-time heat record last week with a face-melting high of 108.7 degrees. And France was just one of many European countries roasting in a week-long heat wave that sent temperatures soaring across the continent.
In D.C., hot and humid summers are pretty much the norm, and it’s not unusual for the heat index (which measures how hot it feels) to breach 100 degrees. But days that actually hit 100 degrees are becoming more frequent, and the District has seen a steady increase in average temperatures over the past few decades. Unless there’s a major reduction in greenhouse gas emissions, get ready for nearly six weeks where it feels like 100 degrees in 2050.
Despite all these changes, Washington hasn’t broken its all-time heat record in nearly 90 years. The hottest day ever recorded in the District was on July 20, 1930, when temperatures reached a blistering 106 degrees.
Ray Martin, a local meteorologist for the National Weather Service, says there’s no guarantee that we’ll be breaking that record any time soon. “That was a pretty unique event,” says Martin. “It’s a very rare thing. The wind direction had to be just right.”
On that day, hot air from the deserts of Northern Mexico traveled directly to the Washington region from the south. But for that to happen, a “perfect pattern” of atmospheric conditions needs to be met, and rising average temperatures don’t necessarily play a role in that process, Martin says.
“Although the average temperatures have been higher, we just haven’t had the perfect airflow to bring that super hot Mexican air up to our area and produce an all-time record here,” he says.
That being said, while we may not breach 106 degrees in the near future, the District has broken a number of other climate records in recent years.
Here’s a breakdown of some of Washington’s most recent climate milestones.
A 148-year rain record
The deluge of rain that hit the Washington region earlier this month was the heaviest July 8 rainfall recorded in 148 years. At National Airport, it rained 3.3 inches in just one hour. The flash flooding left dozens of people stranded in their cars and caused millions of dollars in damages across the region.
The wettest year on record
July’s record-setting flash flooding comes on the heels of D.C.’s wettest year on record. In 2018, D.C. hit its highest ever precipitation total with 66.28 inches of rain, beating its 1889 record by more than 5 inches.
The warmest Potomac temperature
The Potomac river turned into a lukewarm jacuzzi after this month’s 12-day heat wave. The water at Little Falls rose to 93.7 degrees on July 21, the highest temperature on record for that location. It topped the two previous records from 2011 and 2012, although it’s important to note that measurements only date back to 2008.
The warmest fall on record
If you were hoping to cool down in autumn, don’t get your hopes up too soon. In 2016, D.C. experienced its warmest fall on record. Temperatures averaged 63.9 degrees throughout September, October, and December of that year, beating the previous record by 0.6 degrees.
70 percent of D.C.’s hottest summers have occurred since 2000
While the record for hottest summer hasn’t budged since 1980, it’s worth noting that seven of D.C.’s 10 hottest summers have happened since the year 2000.
