Since the beginning of April, temperatures have tended on the cool side of normal in the D.C. area. But the region faces a blast of heat Friday through Sunday, with temperatures set to leap above typical mid-July levels.
Although humidity levels won’t be oppressively high, it will be muggy enough that it feels several degrees hotter than the actual air temperature, or close to 100.
The heat is coming a bit on the late side. In an average year, Washington would have hit 90 degrees by May 16, but 2022′s first 90-degree date will probably be Friday, May 20.
While this first 90-degree day is a few days delayed, Saturday’s predicted high in the mid-90s is early for such temperatures. Washington’s average first 95-degree day is not until June 18.
Any region’s first instance of excessive heat is potentially most dangerous, as people aren’t yet acclimated to high temperatures. Older adults, outdoor workers, people without access to air conditioning and young children are particularly vulnerable to heat-related illness.
“The abrupt beginning of hot temperatures early in the season after a relatively cool spring brings an increased risk of heat illnesses unless proper precautions are taken,” the National Weather Service wrote in a special statement. “Reschedule strenuous activities to early morning or evening. Plan to wear lightweight and loose fitting clothing, and seek shade from the sun. Schedule frequent rest breaks in shaded or air conditioned environments.”
The Weather Service also frequently urges motorists to never leave a child or pet in a car, which can quickly heat up to dangerous levels. Twenty-three children died in hot cars in 2021 across the United States.
Human-caused climate change and urbanization increase the intensity, frequency and duration of the type of heat the area is about to endure.
The extreme heat has its origins in Texas, where numerous locations have soared into the triple digits for days. It will affect much of the Ohio Valley and East Coast over the next few days. The heat may actually be most intense in parts of the Northeast on Saturday; highs could near 100, flirting with all-time May records in a few locations.
The hot weather will last three days in the Washington region, with predicted high temperatures at or above 90 degrees Friday through Sunday. Friday’s highs will probably range from 91 to 95 degrees — about 15 degrees above average highs in the upper 70s. It will mark the first 90-degree day in the region since September.
Computer models project that highs will reach 94 to 98 degrees on Saturday, about 20 degrees above average.
The heat will ease only slightly on Sunday, with forecast highs of 91 to 96.
Assuming that highs hit at least 90 each day Friday through Sunday, this will be the area’s first heat wave of 2022. Washington’s average first heat wave doesn’t occur until June 13.
A cool front passing Sunday night will bring much cooler weather on Monday, with highs in the 70s.
Records will be threatened
Temperatures on Saturday will challenge May 21 records at all three official observing locations in the area. The numbers to beat are 96 from 1934 in Washington and Baltimore, and 92 from 1996 at Dulles.
While it’s not likely that any of these locations will break monthly records, some could come close. Washington would need to hit 99, the monthly record established on May 31, 1991. Baltimore has reached 98 several times in May, most recently in 2011. Dulles has a much shorter record than either of those locations but soared as high as 97 in May 1969.
If Washington hits 96 — as forecast by the National Weather Service — it would be the highest May temperature this early since it was 96 on May 19 in 1997. The earliest it has hit 96 in May was on the 1st in 1942.
Should the temperature climb to 97, as some models project, it would mark Washington’s hottest temperature observed so early in May.
It’s probable that this heat will be the most extreme for May in at least a decade. The last time Washington reached the mid-90s or higher in May was in 2011. It reached 96 on the 30th and 98 on the 31st that year.