Extreme heat warnings, the highest level of alert, were issued for Washington, Baltimore, Philadelphia, eastern North Carolina and much of southeastern Virginia, where temperatures are expected to approach 100 degrees and the heat index, which takes into account humidity and measures how hot it feels, to 105 to 110 degrees.
Heat advisories are in effect for a wide area including Boston, New York, Richmond and Raleigh, N.C. The heat and humidity have eased slightly.
The hottest days are expected to be Monday and Tuesday, with temperatures likely to reach triple digits from South Carolina to Maryland. These temperatures will be about 10 to 15 degrees above normal for the hottest part of the year.
The National Weather Service described it as “extremely dangerous and potentially deadly heat.”
Overnight temperatures will remain well above normal, dropping only into the low 80s F in some areas, without much relief.
The Met Office’s heat risk level of 0 to 4 is expected to reach levels 3 and 4 in many parts of the East Coast through Wednesday, and numerous records will be set for both daytime maximum temperatures and warm nights, with some places breaking records over multiple days.
Several temperature records have already been set, including 101 degrees Fahrenheit in Washington, D.C., on Sunday.
A cold front will move through Wednesday and Thursday, bringing a chance of thunderstorms and keeping temperatures at or below normal through the weekend, but there are signs that heat will return after that.
Here’s a look at how high temperatures will be by Wednesday, city by city.
Along Interstate 95
WASHINGTON — Heatstroke warning, maximum temperature 100 degrees
A record high of 101 degrees will be reached on Sunday, with more triple-digit highs possible in the coming days. Expect a few afternoon storms amid sweltering humidity and heat index temperatures reaching 105 or 110 degrees through at least Tuesday.
- Monday: High 100 degrees
- Tuesday: High 100 / Low 78
- Wednesday: High 97 / Low 80
Baltimore — Heat stroke warning, high temperature 102 degrees.
Plenty of sunshine will mix with midday and afternoon bubbly clouds and a slight chance for storms, with heat indexes of 110 and above possible Monday and Tuesday.
- Monday: High of 101 degrees
- Tuesday: High 102 degrees / Low 76 degrees.
- Wednesday: High 97 / Low 78
Philadelphia — Heat warning, high of 100
Hot, humid and hazy weather will continue. Heat index temperatures will rise above 105 degrees Monday and Tuesday, with overnight lows near 80 degrees. Air quality warnings are also in effect. A strong storm could be driven by a cold front on Wednesday.
- Monday: High 98 degrees
- Tuesday: High 100 / Low 77
- Wednesday: High 96 / Low 80
New York City — Heatstroke warning, high of 96 degrees
Rain falling in the area early Monday morning may only increase humidity rather than relieve the heat. Heat indexes will rise to around 100 degrees Monday and Wednesday, and near 105 degrees on Tuesday. Storms are likely to develop late Wednesday.
- Monday: High 95 degrees
- Tuesday: High 96 / Low 77
- Wednesday: High 93 / Low 80
Boston — Heat stroke warning, high temperature 94 degrees
Monday and Tuesday will see mostly sunny skies with temperatures near the water rising to near the mid 90s F. A chance for rain and storms will develop late Wednesday.
- Monday: High 92 degrees
- Tuesday: High 94 / Low 74
- Wednesday: High 92 degrees / Low 75 degrees.
Other locations
Charlotte — No alerts, up to 99
Heat indexes will be around 100 to 105 and it will be mostly sunny, with a few localized storms possible in the afternoon or evening.
- Monday: High 99 degrees
- Tuesday: High 97 / Low 75
- Wednesday: High 95 / Low 77
Charleston, South Carolina — Heat warning, high of 98 degrees
The combination of extreme humidity and very high temperatures will bring extremes to coastal areas around Charleston, with heat index values approaching 115.
- Monday: High 98 degrees
- Tuesday: High 95 / Low 79
- Wednesday: High 95 / Low 79
Roanoke, Virginia — No warnings, up to 100
The days will be sunny and hot, and the humidity will be a little lower than in areas further east, which will keep the heat index in check, but dry or not, 100 degrees will still be hot.
- Monday: High 98 degrees
- Tuesday: High 100 / Low 73
- Wednesday: High 96 / Low 75
Raleigh, North Carolina — Heat stroke warning, high temperature 101 degrees.
The city already broke records this month, with temperatures reaching 106 degrees on July 5. It won’t be as hot this week, but multiple consecutive days with heat index levels above 105 degrees could take their toll.
- Monday: High of 101 degrees
- Tuesday: High 99 / Low 77
- Wednesday: High 95 / Low 77
Hartford, Connecticut — Heat advisory, maximum temperature 95 degrees.
Hartford has already had 17 days this year where temperatures have reached 90 degrees or higher, the second-most on record, and several more records are on the way this week, with heat index values reaching around 100 degrees.
- Monday: High 95 degrees
- Tuesday: High 95° / Low 72°
- Wednesday: High 95 / Low 74
