Blink and you might have missed spring.
Or so it feels like this week, with D.C. temperatures routinely cracking 80 degrees and AC units getting their first workout. The temperature should drop later this week, but by late May we will be deep into D.C.’s remarkable tropical season.
The simple fact that D.C.’s summers are regarded as so oppressive is amazing. Once, when discussing with a Mainer which area of the country has the worst summers, he quickly blurted out “D.C.” A friend from northern Mississippi remarked that there are negligible differences between Washington’s summers and those of his hometown.
Yet, we are located way north of most large Southern cities, all of which have the same insta-sweat quality as the nation’s cap. So do our summers really blaze like theirs do?
I took a look at the average July and August temperatures in D.C. compared to other East Coast humid heavyweights, which seems a fair comparison since all of these cities have enough concrete to create the urban heat island effect that keeps urban dwellers toastier than their rural neighbors year-round. Also, these six cities have similar year-round humidity numbers, though New Orleans and Miami definitely have slight edges. Also included are a city’s ranking in Current Result’s hottest U.S. cities list.
D.C. does not have the harshest summers in the Eastern half of the country, but it is still remarkable Washington’s summer weather is so close to Atlanta’s, especially when Atlanta’s average winter high is 10 degrees higher than Washington’s. In fact D.C.’s December, January and February highs are closer to those in London than those in Atlanta — but once the seasons change, D.C. takes on the flair of a city located hundreds of miles to the south.
More evidence that summers in Washington and our close neighbor Baltimore are impressively hot lie in the U.S. plant hardiness map. Both cities are in zone 8, capable of supporting certain small palm trees — the same hardiness found in Atlanta, Dallas, Tucson, Ariz., and Portland, Ore. This reflects “urban heat islands by showing the downtown areas of several cities (e.g., Baltimore, Maryland, Washington, DC and Atlantic City, NJ) as a full zone warmer than outlying areas,” fine detail that was introduced in 2003. For reference, Owensboro, Ky., despite being located south of Washington, is in zone 6.
So no, we can’t say we have it worse than Louisianans and Floridians. But the sultry warm weather in the DMV’s principal cities is certainly notable, and if you hate the heat, worth complaining about.