“Another absolute scorcher is in store,” the National Weather Service office serving Philadelphia, which is forecast to see record highs, wrote on Wednesday.
The heat has forced some school systems to change operations or even close both the Ohio Valley and Mid-Atlantic.
The ongoing heat wave began Saturday over the central states before spreading into the Mid-Atlantic and Northeast on Sunday and Monday. Dozens of record highs — many around the century mark — have been set from Texas to Minnesota and from Washington to Maine.
While the heat so far has been accompanied by lower humidity than earlier in the summer, it is rising, especially in the Mid-Atlantic, where heat indices — a measure of how hot it feels while factoring in humidity — are forecast to reach or exceed 105 in several locations Wednesday .
Cooler air is now plunging southward from the north-central US, where the heat has come to an end and a new round of wildfire smoke from Canada threatens. This finally hits the East Coast late in the week. But as one heads into the southern tier of the nation, the heat will persist, as it has for most of the past few months.
Prolonged bouts of extreme heat are a hallmark of human-induced climate change, as are these unusually high temperatures.
Tuesday was another day of widespread record or near-record high temperatures across the Carolinas into the Mid-Atlantic. A number of new highs were also set across Texas, including a September record high of 107 in Abilene, also the hottest temperature ever seen so late in the year there.
Calendar day high records set include:
- Raleigh: 98, up from 97 in 1954
- Washington: 99, beating 97 in 1881
- Atlantic City: 94, tying 93 in 1985
- Alpena, Mich.: 92, winning 90 in 1922
- Concord, NH: 92, winning 91 in 2018 and other years
- Islip, NY: 91, surpassing 90 in 1985
- Caribou, Maine: 86, tied 86 in 1983
A record high of 108 degrees was seen in Wichita Falls, Texas with widespread readings over 100 across the state and into Oklahoma. Dallas hit 104, tying the calendar day record. Oklahoma City hit 104 and Houston hit 102, both their hottest for the date.
Similar site numbers also set record lows for the date.
The forecast for Wednesday
On Wednesday, most of the southern states will see highs in the 90s to near 100, but the most unseasonably warm will be centered in the Mid-Atlantic and Northeast, where highs will be about 10 to 20 degrees above normal.
The Weather Service is predicting several dozen record highs, including some in Texas, several in the Carolinas, but, by far, the largest concentration near this Interstate 95 corridor from Maryland to New York — with an extended mid- to upper-decade forecast of the 90's. Record highs near 90 are also expected in Vermont.
Washington area in focus
The Washington area — which is at the epicenter of this heat wave — has seen three straight days of record heat and is predicted to endure one or two more.
Tuesday was the third day in a row with highs in the 90s across the DC metro area.
The District soared to a record high of 99 degrees Tuesday, surpassing 97 in 1881. It marked the District's hottest day of the summer and also its hottest late-year temperature since September 2010, when it was 99 on the 24th.
Both BWI Marshall and Dulles International Airport also set calendar-day highs — reaching 99 degrees, surpassing the old mark of 96. Dulles matched the highest temperature seen in September for the third day in a row. At BWI, mark it first time on record that it has hit at least 97 degrees on three consecutive September days.
Record highs are forecast across the Washington area again Wednesday, when highs could reach 100.
“[Temperatures] it will be much like yesterday, if not a fate[ree] or two warmer,” the Weather Service office in Sterling, Va., wrote Wednesday morning. If the District reaches 100, it will be the first time since August 2016 and the first time in September since 1980.
Overnight lows are also forecast to hover in record territory through Thursday.
Relief will slowly arrive starting later Thursday as highs climb into the mid-90s once again before falling closer to the 90s on Friday and into the 80s over the weekend.
Heat decreases south and west over time
Once the heat recedes over the Mid-Atlantic states late Thursday, the core of more unusually warm temperatures will shrink southward.
The most extreme heat will be centered in Texas where dozens of record highs are forecast Thursday through the weekend. Record-challenging heat will also creep west into the desert Southwest, where extreme heat watches are in effect for parts of Arizona and California.
Parts of Florida could also see some record highs Thursday through Sunday, as has been the case so often since June.
Potentially record-breaking heat may continue to hug the southern tier early next week, too.
After a string of record highs across the Plains and Midwest on Saturday that extended into the Mid-Atlantic Sunday, here are some of the calendar day records set on Labor Day:
Mid-Atlantic and Northeast
- Richmond: 98, up from 95 in 1970
- Washington: 98, up from 96 in 2019
- Baltimore: 99, up from 96 in 2019
- Philadelphia: 96, winning 93 in 2018
- Harrisburg, Pa.: 97, up from 93 in 2015
- Caribou, Maine: 86, winning 85 in 1999
- Lubbock, Texas: 102, winning 101 in 2000
- Dodge City, Kan.: 105, winning 103 in 2000
- Huron, SD: 102, surpassing 100 in 2001
- Minneapolis: 98, tied with 98 in 1925
- Green Bay: 91, up from 90 in 1990
In addition to calendar day records, some locations also saw their hottest September temperatures ever.
On Monday, monthly records were set in Minnesota, with highs of 102 in Benson and Madison and 101 in Marshall. according weather historian Maximiliano Herrera; Borger, Texas, and Lancaster, Pa., also hit monthly highs.
Jason Samenow contributed to this report.
