Heat index topped 100 degrees Sunday; potential for first 100 degree day since 2016 comes Monday

Reporting stations throughout the D.C. area show the “feels like” temperature, known as the heat index, well over 100 degrees for much of the daytime hours on Sunday. Some locations, especially in the District had a heat index over 105.

Temperatures early this week should come close to 100 with a heat index near 110.

It was so hot this morning, even at 9 a.m., Storm Team4’s Somara Theodore said she had to go pick her husband up, who bailed out of his bike ride early. It was already 90 by then.

“These temperatures are no joke,” she wrote.

She advised that if you must go out this afternoon, be sure to have an idea of where you can seek some shade or some air conditioning.

A heat advisory is in effect until 8 p.m. Sunday night.

Some chances exist Sunday afternoon and evening for a pop-up summer storm, but the better chances for sustained rain are halfway through the week, Wednesday and Thursday.

Theodore said the intense daytime heat will persist into the workweek.

Temperatures are expected to reach 100 degrees on Monday, Storm Team4 meteorologist Lauryn Ricketts said, who added that it will feel closer to 110 degrees when humidity is factored in.

The last time D.C. registered a 100 degree temperature was August 2016, per Ricketts.

Daytime highs will persist into the 90s for most of the week with the only relief coming from slightly lower humidity starting Tuesday.

“This upcoming heat wave is going to be even hotter, so be sure to stay hydrated and never leave anyone or pets in a car as temperatures internally rise even faster,” Theodore said.

Heat causes trail closure

The National Parks Service said the Billy Goat Trail’s A segment in C&O Canal Park near Great Falls and the Potomac River would be closed Sunday and Monday due to the heat.

Montgomery County Fire and Rescue Spokesperson Pete Piringer said in a video statement the National Parks Service superintendent decided to close the trail due to the impending heat and the number of incidents emergency crews have dealt with in the past few days.

Multiple people were treated for heat-related issues on Friday while emergency officers provided water to visitors. On Saturday, dozens more came down with heat-related illnesses, but no one was transported to the hospital.

Other nearby trail options will remain open. Visitors should come prepared for the extreme conditions and use caution.

“It is going to be excessively hot,” Piringer said. “We hope that you are hydrated; if you are hydrated today, you will feel better tomorrow.”

Cooling centers 

At D.C. cooling sites, people will be offered a mask which they are required to wear for the entire time they are in the cooling site. Social distancing will be practiced, as people are directed to open seats that are marked with tape to indicate distancing requirements.

Pools and spray parks in the District remain closed, as under ReOpen DC guidelines, communal pools may only start to reopen on the third stage of reopening. D.C. is currently in Phase Two of its reopening. Find a list of cooling sites in D.C. here.

For Maryland and Virginia residents, check with each jurisdiction to see which cooling sites are open:


  • Anne Arundel County — Anne Arundel County’s cooling centers are open through Tuesday from 10 a.m. to 10 p.m., in response to prolonged high temperatures and excessive humidity.
  • Calvert County — The Calvert County Department of Public Safety, Division of Emergency Management, will open two cooling centers in the county for residents who need to take refuge from the heat in a safe, cool place, with safe drinking water available.
  • Charles County — A few locations will be available from 11 a.m. to 7 p.m. for the duration of the heat advisory.
  • Montgomery County — The county’s Office of Emergency Management and Homeland Security announced a heat emergency alert from Sunday at noon until 6 p.m. on Tuesday. Four locations will be open as cooling centers on Sunday from noon to 6 p.m., with people required to wear masks at all times.
  • Frederick County — Four locations will be opened as designated cooling stations during the heat advisory.


  • City of Alexandria — Multiple locations will be available through Tuesday.
  • Arlington County — All county facilities, including community centers and public libraries, are air-conditioned and open to the public.


Sunday: Daytime highs in the upper 90s, cooling overnight only to the high 70s.

Monday: Mostly sunny and hot with a chance of an afternoon scattered storm. Temperatures are expected to reach the upper 90s, with heat index near 110.

Tuesday: Mostly sunny and very hot. Small chance of an afternoon storm. Temperatures forecast for the mid-90s with heat index values near 103.

Wednesday: Clouds with a greater chance of storms in the afternoon. Temperatures are expected to reach the low 90s.

Current Conditions

José Umaña

José Umaña is a digital editor for WTOP. He’s been working as a journalist for almost a decade, covering local news, education and sports. His work has appeared in The Prince George’s Sentinel, The Montgomery Sentinel, Orlando Sentinel, PressBox and The Diamondback.

Federal News Network Logo
Log in to your WTOP account for notifications and alerts customized for you.

Sign up