Extreme Heat Warning Issued for D.C. Region as Heat Index Near 112 Ahead of Fourth of July

A multiday heat wave is building across the D.C. region as temperatures surpassed 100 on Thursday to kick off the run-up to the Fourth of July, with feels-like temperatures reaching 110 in parts of the area.

“Potentially record-breaking heat is expected to take hold of the D”

FFXnow

WTOP reported that Reagan National Airport reached 102 degrees, toppling the record for the date of 101 degrees recorded back in 1898, while Dulles International Airport tied the record-high for the date of 98 degrees set in 1966.

FFXnow

The National Weather Service has extreme heat warnings in effect for both Thursday and Friday, and WTOP said the region will see only slight relief from heat and humidity in the evening with lows dipping below 80 degrees.

WTOP also said heat index values are expected to be around 105 for Independence Day, and that the highest chance for storms Saturday is from 3 p.m. and 8 p.m. according to 7News First Alert Chief Meteorologist Veronica Johnson.

Beyond weather warnings, Metro said it is responding to extreme heat by monitoring rail temperatures on “heat rides” and by lowering train speeds when outdoor rail temperatures top 135 degrees.

WTOP reported that Metro is “adding something new: applying reflective white paint to vulnerable segments, which lowers temps,” and said more than 6,000 feet of track were treated with the paint.

FOX 5 DC

Metro’s chief infrastructure officer Theresa Impastato said chillers and fans in underground stations keep temperatures about six to 10 degrees cooler than outside, and she said Metro monitors in real time conditions across the system.

In the same report, WTOP said Metro is prepared to respond quickly to any equipment issues that could affect customer comfort, as rail temperatures can soar above 135°F and cause bends in the rail due to thermal expansion.

As the heat wave continues into the holiday, WTOP said Friday’s forecast could feature pop-up showers and storms, and that more widely scattered showers and storms are expected for the Fourth of July.

“DC Weather: Extreme heat warning issued Thursday, heat index near 112 degrees WASHINGTON (7News) — The most dangerous stretch of the heat wave begins Thursday”

WJLA

WJLA said an extreme heat warning is in effect from 10 a.m. to 8 p.m. as afternoon temperatures climb to around 102 degrees with heat index values up to 112 degrees, and it described the heat as “dangerous, potentially life-threatening.”

FOX 5 DC reported that on Saturday evening the National Weather Service issued Severe Thunderstorm Warnings for large parts of Maryland, Virginia and West Virginia, with warnings for Baltimore City and parts of Baltimore, Anne Arundel and Howard counties until 7 p.m.

FOX 5 DC also said organizers canceled the National Independence Day Parade in D.C. because of the extreme heat and delayed public entry for the Salute to America program on the National Mall until 5 p.m., while cities and towns across the region postponed or pushed back parade and fireworks start times.