Washington, Baltimore, Philadelphia and much of eastern North Carolina and southeastern Virginia are under the highest heat warning level. In these areas, maximum temperatures are expected to rise to around 100, with heat indexes – a measure of humidity – reaching 105 to 110.
Heat warnings (only for slightly less intense heat and humidity) apply to the larger area, including Boston, New York, Richmond and Raleigh, North Carolina
The hottest weather is expected Monday and Tuesday, with triple-digit high temperatures possible from South Carolina to Maryland. During the hottest times of the year, these temperatures are about 10 to 15 degrees above normal.
The National Weather Service described it as “extremely dangerous and potentially deadly heat.”
Nighttime temperatures will still be much warmer than normal, only dropping into the low 80s in some areas, but that won't bring much relief.
The Bureau of Meteorology expects heat risk levels to reach levels 0 to 4, and levels 3 and 4, for many areas along the east coast by Wednesday. Records will be plentiful, with some locations setting records on multiple days – both for maximum daytime temperatures and warm nights.
Several record highs were set on Sunday, including 101 degrees in Washington, D.C.
A cold front on Wednesday and Thursday will bring the risk of thunderstorms and bring weekend temperatures back to near normal or even below normal. However, there are signs that heat may pick up thereafter.
Here's a look at Wednesday's high temperatures in each city.
Along Interstate 95
Washington – Heat warning, high 100
On Sunday, the index hit an all-time high of 101 points, with more triple-digit highs likely to follow in the coming days. A few afternoon storms are expected with wet conditions and heat indexes as high as 105 or 110 through at least Tuesday.
- Monday: High 100
- Tuesday: 100 high/78 low
- Wednesday: 97 high/80 low
Baltimore — Heat warning, high 102
Plenty of sunshine mixed with clouds midday and afternoon, with only a small chance of storms. The heat index could reach 110 or higher on Monday and Tuesday.
- Monday: High 101
- Tuesday: 102 high/76 low
- Wednesday: 97 high/78 low
Philadelphia — Heat warning, high 100
Hot, humid and hazy weather predominates. The heat index rose to 105 or higher on Monday and Tuesday, with overnight lows approaching 80. Wednesday's cold front could bring severe storms.
- Monday: High 98
- Tuesday: 100 high/77 low
- Wednesday: 96 high/80 low
New York City — Heat warning, high 96
Some rain in the area early Monday won't provide relief from the heat and could end up increasing humidity. The heat index rose to around 100 on Monday and Wednesday, and to around 105 on Tuesday. Storms are likely late Wednesday.
- Monday: High 95
- Tuesday: 96 high/77 low
- Wednesday: 93 high/80 low
Boston — Heat warning, up to 94
Monday and Tuesday will bring plenty of sunshine, with temperatures rising into the 90s, even near water. The chance of showers and storms becomes stronger by late Wednesday.
- Monday: High 92
- Tuesday: 94 high/74 low
- Wednesday: 92 high/75 low
Other locations
Charlotte — No alerts, maximum 99
The heat index will be around 100 to 105, with mostly sunny skies and the possibility of some isolated afternoon or evening storms.
- Monday: High 99
- Tuesday: 97 high/75 low
- Wednesday: 95 high/77 low
Charleston, South Carolina — Heat warning, high 98 degrees
Extreme humidity and extremely high temperatures pushed Charleston and its surrounding coastal areas to their limits. The heat index could be close to 115.
- Monday: High 98
- Tuesday: 95 high/79 low
- Wednesday: 95 high/79 low
Roanoke, VA — No alarm, 100 maximum
The weather was sunny and hot. Slightly lower humidity further east helps keep the heat index in check, but 100 is hot, dry heat or not.
- Monday: High 98
- Tuesday: 100 high/73 low
- Wednesday: 96 high/75 low
Raleigh, North Carolina — Heat warning, up to 101
On July 5, the city's temperature reached 106 degrees Fahrenheit, already a record for the month.
- Monday: High of 101
- Tuesday: 99 high/77 low
- Wednesday: 95 high/77 low
Hartford, Connecticut — Heat warning, high 95
Hartford has had at least 90 days so far this year with 17, the second-most ever so far. There are more questions on the table this week. The heat index rises to around 100.
- Monday: High 95
- Tuesday: 95 high/72 low
- Wednesday: 95 high/74 low
