The relief was palpable.
Richmond, a city known for its drenching rain, saw its wettest June in a decade. according to Sean Sublette, chief meteorologist for the Richmond-Times Dispatch. Because dry air sheds heat faster than moist air at night, the city also recorded its coldest June temperatures since 2012.
Washington has also lost its typical share of hot days and sauna-like nights. On Independence Day, the dew point—a measure of humidity— dropped to 49 degrees, a shockingly low price. Dew averages in July are in the 60s.
Any dew points below 60 are refreshing in the mid-Atlantic this time of year. At the end of June, they even sank into the 30s in Washington, which is practically unheard of.
The nation's capital has yet to see a heat wave this summer, defined as three straight days of 90-degree weather. It has recorded just 12 90-degree days so far, six fewer than normal. The last summer with this few to date was 2009 and had only two heat waves, the first occurring before August.
Capital Weather Gang readers have noticed the silent heat and it is he doesn't complain:
“This has been the mildest summer I can remember in a long time” tweeted @NattyBDC.
“I really liked this weather! Last summer seemed unrelentingly hot and very little rain in July.” tweeted @uwchelsita.
The number of 90-degree days is also down in New York and Boston.
New York has had seven — an almost normal number, but Boston has seen only two, which is three less than typical.
“[S]Since mid-May it has been nothing but wonderful almost every day.” Eric Fisher tweetedchief meteorologist for Boston television station WBZ.
Relief from the heat can be found in the shape of the jet stream, which is the high-altitude wind stream that separates warm and cold air and is the highway for thunderstorms.
While the jet stream has swelled northward over the western and central United States, it has made a splash across the eastern United States, often crossing the Mid-Atlantic. This allowed a somewhat normal stream of dry, cool Canadian air to flow into the northeast.
The jet stream has curled around the Pacific Northwest, where it's also having a relatively mild summer — a welcome break from last year's historic heat wave.
But for areas south of the jet stream—in the central and southern United States—the heat has been punishing and persistent. Texas has been hit particularly hard.
However, good weather in the Northeast comes at a cost. Because it has remained north of the storm track, very little precipitation has fallen. Moderate to severe drought has developed from eastern Connecticut to southern Maine.
The Mid-Atlantic, meanwhile, was in a prime spot for heavy rainfall — located right along the path of the jet stream. Both Washington and Richmond have been hit by severe storms in recent weeks. The Washington area has also seen many instances of flooding, as have many locations in its southwest.
While much of the Mid-Atlantic and Northeast have avoided long periods of extreme heat and temperatures are hovering near the recent 30-year average, temperatures are still elevated compared to historical averages.
Average summer temperatures so far this year in Richmond, Washington, New York and Boston rank among the top 45 warmest in the past 125 to 150 years. In other words, this summer's weather would have been unusually warm a century ago, even if it's considered normal now—a testament to the influence of human-caused climate change.
Computer models signal a warming trend in the coming week.
Richmond and Washington are predicted to see highs in the 90s, while New York and Boston are predicted to be near 90.
Instead of taking a dive to the northeast, the jet stream is forecast to flatten out and run slightly northward — shifting enough to allow some heat to swell into the region.
As we head into August, it's unclear whether the jet stream will shift further north, causing the nor'easters to bake, or return to the dip.
The National Weather Service leans slightly toward a warmer than normal first half of August for much of the eastern United States.
Even if it warms up a bit, average temperatures begin to drop very slowly in late July across much of the Northeast. Average temperatures begin to drop on July 21 in Washington and July 26 in Boston.
